Soluble Sugar Content Research Articles

Proline Priming Enhances Seed Vigour and Biochemical Attributes of Rice (Oryza sativa L.) during Germination.

Seed vigour is a desirable trait especially for direct seeded rice (DSR) cultivation. Seeds with high vigour could improve seed germination, support seedlings in competing with weeds for water and nutrients, and improving seedling establishment throughout the early stages of crop growth. The success of DSR system which account for more 25% of world cultivation areas is highly dependent on the seed vigour and seedling establishment. Seed priming is a promising technique to improve seed vigour. Proline is an amino acid that has been well studied for its roles in plants under different environmental stress conditions. Nevertheless, the effect of proline as a seed priming agent in improving seed vigour in rice remain elusive. In this research, the effect of 24 h of proline priming at various concentrations (0 mM, 1 mM, 2 mM, 10 mM and 20 mM) on rice seed vigour, amylase activity, and total soluble sugar (TSS) content of a Malaysia indica rice variety, MR269 was investigated. Results showed that seeds primed with lower concentration of proline (0 mM, 1 mM and 2 mM) had better germination responses while priming at high concentrations (10 mM and 20 mM) reduced seed germination. Among the concentration tested, priming with 1 mM proline enhanced seed vigour with significantly higher germination percentage (GP), germination rate index (GRI) and seedling vigour index (SVI). In addition, proline primed seeds also exhibited increased amylase activity and TSS content as compared to unprimed seeds. However, priming seed with 20 mM proline was detrimental to the seed vigour and seedling growth whereby lower GP, GRI and SVI and higher mean germination time (MGT) were observed. In short, this study shows that proline could be a potential seed priming agent to improve seed vigour in rice.

Plant Beneficial Desert Actinomycete, Modestobacter caceresii KNN 45-2bT, Promote Growth of Tomato (Lycopersicum esculentum Mill.) under Drought Condition

Drought stress is currently the most serious challenge to global food security and agricultural productivity. Desert actinobacteria have gained attention as potential candidates for enhancing plant growth in water stress environments. In this regard, a desert actinomycete, namely Modestobacter caceresii strain KNN 45-2bT, was selected to investigate its plant growth promoting abilities and drought tolerance. Next, this desert strain was inoculated to tomato (Lycopersicum esculentum Mill.) under drought, and the results included increases in root length, shoot and root fresh weight, shoot and root dry weight, total fresh weight and dry weight, fruit weight, proline accumulation, total soluble sugar content and trolox content. Stress treatments on the bacterized tomato plants also resulted in the reduction of hydrogen peroxide accumulation. Putative proteins coding sequences conferring plant growth promoting (PGP) traits (IAA production, phosphate solubilization, siderophore production, nitrogen fixation) and drought response (biosynthesis of proline metabolism, oxidative and osmotic stress response) were also detected from their genomic analyses. In conclusion, these results provide credence to the idea that the inoculation of tomato plants with plant beneficial desert actinomycete is an effective method of combating the negative effects of drought stress.

Differences in Physicochemical Properties of Stems in Oat (Avena sativa L.) Varieties with Distinct Lodging Resistance and Their Regulation of Lodging at Different Planting Densities.

Planting density is an effective strategy for regulating both oat lodging and forage quality. To delve into the regulatory mechanisms of planting density on lodging and oat forage quality, lodging-resistant variety LENA and lodging-sensitive variety QY2 were grown in 2018 and 2019 growing seasons, and four planting densities were implemented: 2.25 × 106 plants/ha (D1), 4.5 × 106 plants/ha (D2), 6.75 × 106 plants/ha (D3), and 9 × 106 plants/ha (D4). At the milk stage, we measured the contents of potassium, calcium, magnesium, silicon, lignin, crude fiber, starch, soluble sugar, and soluble protein in the second and third stem internodes of the plants. The results revealed the lodging-resistant variety LENA demonstrated significantly higher contents of calcium, potassium, silicon, crude fiber, lignin, and lower contents of starch, soluble sugar, and soluble protein (p < 0.01). Similar trends in the physicochemical properties of stem internodes for both oat varieties with increasing planting density. Crude fiber, soluble sugar, magnesium, starch, potassium, and lignin were the key characteristics affecting the lodging coefficient, and variety and planting density affected the lodging coefficient mainly by regulating the synthesis of starch, soluble sugar, and crude fiber. At planting density D3, stem internodes exhibited higher physicochemical properties and a lower lodging coefficient, favoring oat forage production. The results offer a valuable theoretical foundation and practical reference for oat lodging-resistant cultivation.

Investigation of Drought Stress on Chickpea (Cicer arietinum L.) Genotypes Employing Various Physiological Enzymatic and Non-Enzymatic Biochemical Parameters.

Drought stress is a universal crisis in sustaining the growth and production of major legumes, including the chickpea. Drought severely reduces the biomass of chickpea plants, with the effect on leaves appearing the most apparent. The aim of this study was to investigate, using various physiological and biochemical markers throughout the pod filling stage, how 78 desi chickpea genotypes tolerated drought stress. Most of the evaluated characteristics showed significant variations between control and drought treatments. The mean performance of most of the investigated parameters significantly decreased under moisture-stressed conditions. RWC, SWD, MSI, and CTD were investigated under terminal drought-stressed conditions. Except for saturated water deficit (SWD), all remaining characteristics declined with increasing stress. Genotypes SAGL152210, SAGL152252, SAGL152347, SAGL22-115, and JG11 were recognized as drought-tolerant based on physiological characteristics. Biochemical markers viz., protein content, total soluble sugar, lipid peroxidation, and proline content, had an impact on osmotic adjustment. Based on non-enzymatic biochemical traits, genotypes SAGL22-115, ICC4958, ICCV201108, ICCV201107, SAGL152252, and JG11 were identified for their capability to survive under drought-stressed conditions. H2O2 content, CAT, SOD, POD, APX, and DPPH were considered antioxidant agents. Genotypes SAGL152208, SAGL22-105, SAGL22-112, ICC201108, SAGL152278, SAGL152252, SAGL162371, SAGL162390, ICC 4958, and JG315 may be considered drought-tolerant based on antioxidant activities. These genotypes are believed to be better equipped with physio-biochemical mechanisms and antioxidant defense systems at the cellular level and can be used in breeding programs to breed drought-tolerant cultivar(s). They can also be screened in the future, allowing the line(s) that have remained consistent over time to be recognized and registered as drought-tolerant donors.

Transcriptome and Metabolome Analyses Reveal the Molecular Mechanisms of Albizia odoratissima’s Response to Drought Stress

Albizia odoratissima is a deciduous tree species belonging to the family Leguminosae. It is widely distributed in the southern subtropical and tropical areas of China and has important ecological and economic value. The growth and metabolic processes of A. odoratissima are affected by drought stress, but the molecular mechanisms remain unknown. Therefore, this study investigated the physicochemical properties, gene expression, and metabolites of A. odoratissima seedlings under drought stress. The results show that, in leaves of A. odoratissima seedlings, drought stress reduced the moisture content, chlorophyll content, photosynthetic efficiency, superoxide dismutase (SOD) activity, and gibberellin (GA) and indoleacetic acid (IAA) contents while increasing the catalase (CAT) and peroxidase (POD) activities and malondialdehyde (MDA), proline, soluble sugar, and soluble protein contents. Within the CK5 (Day 5 of control group) vs. T5 (Day 5 of drought treatment), CK10 vs. T10, CK15 vs. T15, and CK20 vs. T20 groups (CK: control group; T: drought treatment), a total of 676 differentially expressed genes (DEGs) were upregulated and 518 DEGs were downregulated, and a total of 228 and 143 differential accumulation metabolites (DAMs) were identified in the CK10 vs. T10 and CK20 vs. T20 groups. These were mainly involved in the amino acid and alkaloid metabolism pathways in the leaves of the A. odoratissima seedlings. In the amino acid and alkaloid biosynthesis pathways, the relative expression levels of the AoproA (Aod04G002740, ORTHODONTIC APPLIANCE), AoOAT (Aod07G015970, ORNITHINE-OXO-ACID TRANSAMINASE), and AoAOC3 (Aod12G005010/08G003360/05G023920/08G003000/08G003010, AMINE OXIDASE COPPER CONTAINING 3) genes increased, which concurrently promoted the accumulation of arginine, proline, piperine, cadaverine, and lysine. Furthermore, some key transcription factors in the response to drought were identified in the leaves using the weighted gene co-expression network analyses (WGCNA) method. These findings reveal that A. odoratissima seedlings respond to drought stress by improving the capacities of the antioxidant system and secondary metabolism.

Alleviating Effects of Methyl Jasmonate on Pepper (Capsicum annuum L.) Seedlings under Low-Temperature Combined with Low-Light Stress.

Low temperature combined with low light (LL) is an important factor limiting pepper quality and yield. 'Hang Jiao No. 2' were used as experimental materials, and different concentrations of MeJA (T1 (0 μM), T2 (100 μM), T3 (150 μM), T4 (200 μM), T5 (250 μM) and T6 (300 μM)) were sprayed under LL stress to explore the positive effect of exogenous methyl jasmonate (MeJA) on peppers under LL stress. The photosynthetic properties, osmoregulatory substance, reactive oxygen species, antioxidant enzyme activities, and related gene expressions of the peppers were measured. Our results demonstrated that 200 μM MeJA treatment significantly increased chlorophyll content, light quantum flux per active RC electron transfer (Eto/RC), maximum captured photonic flux per active RC (TRo/RC), energy flux for electron transfer in the excitation cross section (Eto/CSm), energy flux captured by absorption in the excitation cross section (TRo/CSm), soluble protein, and soluble sugar content. Moreover, it significantly improved the maximum photochemical efficiency of PSII (Fv/Fm) and performance index based on absorbed light energy (PI (abs)) by 56.77% and 67.00%, respectively, and significantly decreased malondialdehyde (MDA) content and relative conductivity by 30.55% and 28.17%, respectively. Additionally, antioxidant enzyme activities were elevated, and the expression of the related genes was activated in pepper seedlings under stress, leading to a significant reduction in reactive oxygen species content. In conclusion, our findings confirmed that 200 μM MeJA could reduce the injury of LL to pepper leaves to the photosynthetic organs of pepper leaves, protect the integrity of the cell membrane, and further improve the tolerance of pepper seedlings to LL.

Identification of Cold Tolerance Transcriptional Regulatory Genes in Seedlings of Medicago sativa L. and Medicago falcata L.

Alfalfa species Medicago sativa L. (MS) and Medicago falcata L. (MF), globally prominent perennial leguminous forages, hold substantial economic value. However, our comprehension of the molecular mechanisms governing their resistance to cold stress remains limited. To address this knowledge gap, we scrutinized and compared MS and MF cold-stress responses at the molecular level following 24 h and 120 h low-temperature exposure (4 °C). Our study revealed that MF had superior physiological resilience to cold stress compared with MS, and its morphology was healthier under cold stress, and its malondialdehyde content and superoxide dismutase activity increased, first, and then decreased, while the soluble sugar content continued to accumulate. Transcriptome analysis showed that after 120 h of exposure, there were different gene-expression patterns between MS and MF, including 1274 and 2983 genes that were continuously up-regulated, respectively, and a total of 923 genes were included, including star cold-resistant genes such as ICE1 and SIP1. Gene ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses revealed numerous inter-species differences in sustained cold-stress responses. Notably, MS-exclusive genes included a single transcription factor (TF) gene and several genes associated with a single DNA repair-related pathway, whereas MF-exclusive genes comprised nine TF genes and genes associated with 14 pathways. Both species exhibited high-level expression of genes encoding TFs belonging to AP2-EREBP, ARR-B, and bHLH TF families, indicating their potential roles in sustaining cold resistance in alfalfa-related species. These findings provide insights into the molecular mechanisms governing cold-stress responses in MS and MF, which could inform breeding programs aimed at enhancing cold-stress resistance in alfalfa cultivars.

Impact of regulated deficit irrigation on the dynamics of quality changes in processing tomato fruits during ripening

Quality is a key factor restricting the development and economic benefits of the tomato processing industry, and improving the quality of tomatoes has become a hotspot in the development of the tomato processing industry in Xinjiang. Regulated deficit irrigation (RDI) is an abiotic means of crop yield and quality control widely used for crop yield and quality improvement. This study aimed to investigate the impact of RDI on the dynamics of quality changes in processing tomato fruits during ripening via a 2-year (2022–2023) filed experiment with five water irrigation treatments in Xinjiang, China. The results showed that compared with conventional irrigation, regulated deficit irrigation significantly saved 315–1260 m3 ha−1 irrigation water. Mild RDI increased the single fruit weight and fruit hardness by 0.15 % and 3.29 kg cm2, respectively, thus improved the yield and storage and transportation quality of processed tomatoes. Moderate RDI increased the contents of soluble solid, soluble sugar and lycopene in fruit to 0.6 %, 0.56 % and 3.53 μg/g, respectively, therefore significantly improved the nutritional quality and flavor quality of processed tomato. Ultimately, a comprehensive evaluation using a coupled Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS) model, taking into account the appearance, nutrition, flavor, and storage and transportation indexes of processed fruits, concluded tha W1 treatment is a sustainable water management approach that balances yield and quality. Therefore, the optimal deficit irrigation model for processing tomato fruits in Xinjiang was recommended to be the W1 treatment, whereas the W2 treatment was considered as an alternate model. The study supported the large-scale development of the tomato processing industry in Xinjiang and the implementation of effective water-saving farming.

Halotolerant Enterobacter asburiae A103 isolated from the halophyte Salix linearistipularis: Genomic analysis and growth-promoting effects on Medicago sativa under alkali stress

Soil salinization negatively affects plant growth and threatens food security. Halotolerant plant growth-promoting bacteria (PGPB) can alleviate salt stress in plants via diverse mechanisms. In the present study, we isolated salt-tolerant bacteria with phosphate-solubilizing abilities from the rhizosphere of Salix linearistipularis, a halophyte distributed in saline-alkali soils. Strain A103 showed high phosphate solubilization activity and was identified as Enterobacter asburiae based on genome analysis. In addition, it can produce indole-3-acetic acid (IAA), siderophores, and 1-aminocyclopropane-1-carboxylate (ACC) deaminase. Genome mining has also revealed the presence of several functional genes involved in the promotion of plant growth. Inoculation with A103 markedly improved alfalfa growth in the presence of 100 mM NaHCO3. Under alkali stress, the shoot and root dry weights after bacterial inoculation improved by 42.9 % and 21.9 %, respectively. Meanwhile, there was a 35.9–37.1 % increase in the shoot and root lengths after treatment with A103 compared to the NaHCO3-treated group. Soluble sugar content, peroxidase and catalase activities increased in A103-inoculated alfalfa under alkaline stress. A significant decrease in the malondialdehyde content was observed after treatment with strain A103. Metabolomic analysis indicated that strain A103 positively regulated alkali tolerance in alfalfa through the accumulation of metabolites, such as homocarnosine, panthenol, and sorbitol, which could reduce oxidative damage and act as osmolytes. These results suggest that halophytes are valuable resources for bioprospecting halotolerant beneficial bacteria and that the application of halotolerant growth-promoting bacteria is a natural and efficient strategy for developing sustainable agriculture.

IN VITRO CHARACTERIZATION AND ANALYSIS OF RICE VARIETIES AGAINST VARIOUS LEVELS OF SALT STRESS

Salinity is a significant environmental factor that greatly impacts plant yield, particularly in arid and semi-arid regions. The study examined the response of two rice varieties (Swat-1 and Pakhal) to salinity stress on the callus. Various salt concentrations were utilized. Among the two varieties, Swat-1 displayed the highest rate of callogenesis in the initial results. The Calli were exposed to varying concentrations of salt (50mM, 100mM, and 150mM), with each concentration tested in three replicates. Under the influence of stress, Swat-1 experienced a decrease in its Relative growth rate (RGR), whereas Pakhal remained steady at 50mM and 100mM. It was only at 150mM that Pakhal also exhibited a decline in RGR. Regarding water content, the stress caused a decrease in the content. At the highest stress level (150mM), the lowest water content was observed. The impact on soluble sugars was also noteworthy. As stress levels rose, concentrations of total sugars also increased. Similar findings were noted for proline, with stress leading to an increase in its concentration. Out of the two varieties, Pakhal appeared to have the highest proline accumulation. Similarly, there was a noticeable upward trend observed in catalase activity. There was a significant increase in catalase activity in both varieties after being exposed to stress for 30 and 60 days. The findings indicate that both varieties effectively developed strategies to combat salinity stress. They exhibited high concentrations of total soluble sugars and proline, as well as demonstrated significant catalase activity.

Effect of Drought and Rehydration on Physiological Characteristics of Agriophyllum squarrosum (L.) Moq. in Different Habitats.

Agriophyllum squarrosum (L.) Moq. is a highly prevalent xerophytic species found throughout northern China. It is suitable for cultivation in semi-arid sandy environments and may establish roots in arid desert locations. This species plays a pioneering and exploratory role in the colonization of desert plants. In this study, we selected A. squarrosum from the Urat desert steppe (UD) and Horqin sandy land (HS) to explore their adaptation mechanisms to drought and rehydration environments by using the pot weighing control method to simulate an arid environment. The findings showed that the control (watering to 60-65% of field capacity) exceeded its required amount and the leaves turned yellow. The chlorophyll content was lower than those under moderate and severe drought, and rehydration caused a decrease. However, the contents of malondialdehyde, soluble sugar, and proline in the drought treatment were higher than those in the control. Under moderate and severe drought, the chlorophyll content and the quantum efficiency of photosystem II (Fv/Fm) of A. squarrosum from UD were higher than those from HS. During drought and rehydration processes, the proline content was relatively lower, while the activities of peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) and the content of soluble sugar and soluble protein were higher. However, antioxidant enzymes and osmoregulators from UD were higher than those from HS. The results suggest that the stronger ability of A. squarrosum to endure drought environments in UD is due to the high level of antioxidant enzymes and osmoregulators, which are conducive to relieving cell membrane damage when subjected to drought and rehydration.

Hydrogen sulfide alleviates cadmium stress in germinating carrot seeds by promoting the accumulation of proline

Carrot (Daucus carota L.), a widely cultivated economically vegetable from the Apiaceae family, is grown globally. However, carrots can be adversely impacted by cadmium (Cd) pollution in the soil due to its propensity to accumulate in the fleshy root, thus impeding carrot growth and posing health hazards to consumers. Given the potential of hydrogen sulfide (H2S) to improve plant resistance against Cd stress, we treated germinating carrot seeds with varying concentrations of sodium hydrosulfide (NaHS), aiming to alleviate the toxic impacts of Cd stress on carrot seed germination. The results revealed that carrot seeds treated with a concentration of 0.25 mM NaHS displayed better seed germination-associated characteristics compared to seeds treated with NaHS concentrations of 0.1 mM and 0.5 mM. Further investigation revealed a rise in the expression levels of L-cysteine desulfhydrase and D-cysteine desulfhydrase, along with enhanced activity of L-cysteine desulfhydrase and D-cysteine desulfhydrase among the NaHS treatment group, thereby leading to H2S accumulation. Moreover, NaHS treatment triggered the expression of pyrroline-5-carboxylate synthase and pyrroline-5-carboxylate reductase and promoted the accumulation of endogenous proline, while the contents of soluble sugar and soluble protein increased correspondingly. Interestingly, since the application of exogenous proline did not influence the accumulation of endogenous H2S, suggesting that H2S served as the upstream regulator of proline. Histochemical staining and biochemical indices revealed that NaHS treatment led to elevated antioxidant enzyme activity, alongside a suppression of superoxide anion and hydrogen peroxide generation. Furthermore, high performance liquid chromatography analysis revealed that NaHS treatment reduced Cd2+ uptake, thereby promoting germination rate, seed vitality, and hypocotyl length of carrot seeds under Cd stress. Overall, our findings shed light on the application of NaHS to enhance carrot resistance against Cd stress and lay a foundation for exploring the regulatory role of H2S in plants responding to Cd stress.

Dopamine Regulates Its Own Synthesis via MdORG2 to Improve Low-Nitrogen Tolerance in Apple Plants.

Nitrogen (N) is crucial for plant growth and development. Exogenous dopamine has been shown to improve the N-deficiency tolerance of apple. However, the potential regulatory mechanisms by which dopamine mitigates low-N stress remain unclear. Our data indicated that the dopamine levels in apple (Malus domestica) were elevated by the overexpression (OE) of MdTYDC, which encodes tyrosine decarboxylase, a key enzyme in dopamine biosynthesis. The photosynthetic capacity of the OE lines was enhanced, and the root system was more extensive under low-N stress compared with the wild-type (WT) plants. This enhancement contributed to a greater net nitrate influx at the root surface in the OE lines compared with the WT. Transcriptomic and carbohydrate analyses suggested that the OE of MdTYDC in apple enhanced N-deficiency tolerance by promoting the expression of carbohydrate-related genes, which increased the content of soluble sugars and sorbitol. Both exogenous dopamine and MdTYDC OE activated the expression of MdORG2 (a bHLH transcription factor), which, in turn, directly binds to the promoter of MdTYDC, activating its expression, increasing dopamine levels, and consequently conferring strong low-N tolerance in apple. Thus, this reveals the molecular pathways by which dopamine regulates low-N tolerance in apple through pathways involving MdTYDC and MdORG2.

The Influence of Microalgae Fertilizer on Soil Water Conservation and Soil Improvement: Yield and Quality of Potted Tomatoes

We aim to study the impact of microalgae fertilizer on soil nutrients, water conservation and crop yield and quality while also determining the optimal ratio of microalgae fertilizer to chemical fertilizer. Using “Xinoufen No.9” tomatoes as the test subject, we conducted pot experiments with four different treatments: control with 100% chemical fertilizer (CK), T1 (25% microalgae fertilizer + 75% regular chemical fertilizer), T2 (75% microalgae fertilizer + 25% regular chemical fertilizer) and T3 (100% microalgae fertilizer). The results show that an increased application of microalgae fertilizer enhanced the soil organic matter, ammonium nitrogen, available phosphorus and potassium content. T3 showed the most improvement followed by T2. The co-application of microalgae fertilizer with chemical fertilizer can significantly increase the stem girth, plant height and yield of tomatoes. At the same time, microalgae fertilizer effectively regulates leaf stomatal conductance, promoting tomato leaf respiration. As the stomatal conductance increases, the transpiration rate and net photosynthesis rate of all treatments improve, followed by a decline in intercellular CO2 concentration, with T2 exhibiting the best performance. Among all treatments, T2 treatment yielded the highest per-plant production (0.630 kg), followed by T3 (0.521 kg). This is because the microalgae fertilizer promotes the distribution of photosynthetic products to the fruit, enhancing the yield and quality of tomatoes. Additionally, the microalgae fertilizer also increases the content of soluble sugars, soluble protein, vitamin C and lycopene in the fruit while reducing the nitrate content. Compared to the control group CK, T2 increases the content of soluble sugars, vitamins and lycopene by 26.74%, 39.29% and 158.31%, respectively. Microalgae fertilizer also helps to improve soil water and thermal conditions, enhancing the water-use efficiency of tomatoes. Compared to CK, the water-use efficiency of T2 treatment increased by 54.05%. Correlation analysis indicates that water and fertilizer factors significantly affect tomato yield, with a correlation exceeding 70%. The net photosynthesis and transpiration rates significantly influence fruit quality, with correlations above 80%. By applying microalgae fertilizer, the efficiency of water and fertilizer use can be effectively improved, thus achieving the goal of water conservation and quality enhancement. Therefore, through comprehensive analysis, using the membership function method of indicators such as soil environment, crop yield, fruit quality and water-use efficiency, it is concluded that T2 is the optimal fertilization treatment. This study provides theoretical support for the application of microalgae biofertilizer technology in the cultivation of tomatoes and other vegetables in the northern, cold and arid regions.

Assessing the Preservation Effectiveness: A Comparative Study of Plasma Activated Water with Various Preservatives on Capsicum annuum L. (Jalapeño and Pusa Jwala)

The study investigates the efficacy of plasma-activated water (PAW) in preserving green chillies (jalapeño and pusa jwala) and compared it with various household fruits and vegetables cleaners’ solutions. PAW was prepared using a pencil plasma jet with air as the plasma forming gas. The results of visual analysis revealed that PAW-treated chillies maintain their fresh appearance even after 21 days, exhibiting significantly lower spoilage compared to control (ultrapure milli-Q water) and fruits and vegetables cleaners’ solutions. PAW demonstrated antimicrobial properties, effectively reducing microbial growth and spoilage on chillies over the storage period. Physical attributes, such as weight loss and firmness, are evaluated. It has been observed that PAW-treated chillies exhibit lower weight loss and higher firmness, indicating better membrane integrity and moisture retention. Microbial resistance was notably higher in PAW-treated chillies compared to control and when cleaning solutions were used. CIELAB color analysis revealed that PAW-treated chillies retain greenness, and color, freshness, outperforming control and cleaners. Sensory evaluation, including visual inspection, smell, taste, and touch, consistently favored PAW-treated chillies, emphasizing their superiority in terms of enhancement in shelf-life. Biochemical analysis revealed that PAW-treated chillies either maintain or show enhancement in nutritional attributes such as soluble sugar, protein, and ascorbic acid concentrations. Phenol concentration (antioxidant activity) remained stable across treatments. Overall, the study underscores the positive impact of PAW treatment on preserving the membrane integrity, antimicrobial resistance, sensory quality, and nutritional attributes of green chillies, making PAW an alternative for extending their shelf life.

A two-in-one molybdenum disulfide-chitosan nanoparticles system for activating plant defense mechanisms and reactive oxygen species to treat Citrus Huanglongbing

Citrus Huanglongbing (HLB) poses an enormous challenge to Citrus cultivation worldwide, necessitating groundbreaking interventions beyond conventional pharmaceutical methods. In this study, we propose molybdenum disulfide-chitosan nanoparticles (MoS2-CS NPs) through electrostatic adsorption, preserving the plant-beneficial properties of molybdenum disulfide (MoS2), while enhancing its antibacterial effectiveness through chitosan modification. MoS2-CS NPs exhibited significant antibacterial efficacy against RM1021, and the closest relatives to Candidatus Liberibacter asiaticus (CLas), Erwinia carotovora, and Xanthomonas citri achieved survival rates of 7.40 % ± 1.74 %, 8.94 % ± 1.40 %, and 6.41 % ± 0.56 %, respectively. In vivo results showed, CLas survival rate of 10.42 % ± 3.51 %. Furthermore, treatment with MoS2-CS NPs resulted in an increase in chlorophyll and carotenoid content. Concomitantly, a significant reduction in malondialdehyde (MDA), soluble sugar, hydrogen peroxide (H2O2), and starch contents was also observed. Mechanistically, MoS2-CS NPs enhanced the activity of antioxidant-related enzymes by upregulating the expression of antioxidant genes, thereby galvanizing the antioxidant system to alleviate oxidative stress. Collectively, this dual functionality—combining direct antibacterial action with the activation of plant defense mechanisms—marks a promising strategy for managing Citrus Huanglongbing and suggests potential agricultural applications for MoS2-based antibacterial treatments.

Integrated cytological, physiological, and comparative transcriptome profiling reveals the regulatory network for male sterility in Welsh onion (Allium fistulosum L.)

Welsh onion (Allium fistulosum L.) is a specialty crop with value as a vegetable, condiment, and medicine. However, the molecular mechanisms related to pollen abortion and cytoplasmic male sterility are poorly understood, limiting the heterosis utilization and hybrid production of A. fistulosum. This study investigated the dynamic differences between male-sterile (MS) plants and male-fertile (MF) plants at different anther developmental stages based on integrated cytological, physiological, and transcriptomic analyses. Cytological observations revealed that pollen abortion in the MS plants began during the tetrad stage and was caused by vacuolated microspores, abnormal degradation of the tapetum, and inadequate nutrient supply. The physiological results showed that MS plants exhibited low total soluble sugar and starch contents and decreased antioxidant enzyme activities (peroxidase and catalase). Comparative transcriptome analysis identified 7005 differentially expressed genes (DEGs) and functional enrichment analysis indicated that significant transcriptomic differences were related to oxidative phosphorylation, starch and sucrose metabolism, and cutin, suberine, and wax biosynthesis. The relative expression levels of key DEGs in these three important metabolic pathways were determined using quantitative real-time polymerase chain reaction. On this basis, a core transcriptome-mediated MS network was proposed for MS plants with four functional components: inhibited sucrose synthesis and transport; blocked cutin, suberine, and wax synthesis; accelerated reactive oxygen species generation; and abnormal tapetal programmed cell death. These results provide theoretical guidance for further exploring the molecular mechanisms of male sterility in A. fistulosum.

Exogenous application of silica nanoparticles mitigates combined salt and low-temperature stress in cotton seedlings by improving the K+/Na+ ratio and antioxidant defense

Silica nanoparticles (SiO2-NPs) have been demonstrated to alleviate the adverse impacts of salt or low temperature on crop growth, especially for individual stress. The aim of this study was to elucidate the regulatory effect of SiO2-NPs on plant performance under combined salt and low-temperature stress. Therefore, a phytotron experiment was performed to explore the effects of SiO2-NPs application (0, 50, 100, 200 mg L−1) on the plant growth, ionic content, antioxidant activities, photosynthetic parameters, and osmoregulator concentrations of cotton seedlings subjected to the combined stress of salinity (50, 100, and 150 mmol L−1 NaCl) and low temperature (day and night temperatures of 15 and 10 °C). The results indicated that the combinatorial stress strongly decreased the plant height and leaf area of cotton seedlings, and obviously suppressed the aboveground biomass by 10.26 %, 11.42 %, and 15.70 % with the increase in salinity. While SiO2-NPs application significantly increased the plant growth, photosynthetic rate, transpiration rate, stomatal conductance, superoxide dismutase, catalase and glutathione reductase activities, leaf water potential, K+, and proline contents, and reduced the Na+ content and Na+/K+ ratio of cotton seedlings under the combinatorial stress. However, the effects of SiO2-NPs on reduced glutathione, total soluble sugar and protein content, and peroxidase activity did not exhibit a clear pattern. The aboveground biomass of cotton seedlings subjected to the combinatorial stress was closely correlated with the Na+/K+ ratio, Na+ content, K+ content, proline content, SOD activity, and CAT activity, indicating that SiO2-NPs could alleviate the suppression of combinatorial stress on cotton seedling growth by decreasing the Na+/K+ ratio and increasing the antioxidant capacity.

GhPME36 aggravates susceptibility to Liriomyza sativae by affecting cell wall biosynthesis in cotton leaves

BackgroundCotton is an important economic crop and a host of Liriomyza sativae. Pectin methylesterase (PME)-mediated pectin metabolism plays an indispensable role in multiple biological processes in planta. However, the pleiotropic functions of PME often lead to unpredictable effects on crop resistance to pests. Additionally, whether and how PME affects susceptibility to Liriomyza sativae remain unclear.ResultsHere, we isolated GhPME36, which is located in the cell wall, from upland cotton (Gossypium hirsutum L.). Interestingly, the overexpression of GhPME36 in cotton caused severe susceptibility to Liriomyza sativae but increased leaf biomass in Arabidopsis. Cytological observations revealed that the cell wall was thinner with more demethylesterified pectins in GhPME36-OE cotton leaves than in WT leaves, whereas the soluble sugar content of GhPME36-OE cotton leaf cell walls was accordingly higher; both factors attracted Liriomyza sativae to feed on GhPME36-OE cotton leaves. Metabolomic analysis demonstrated that glucose was significantly differentially accumulated. Transcriptomic analysis further revealed DEGs enriched in glucose metabolic pathways when GhPME36 was overexpressed, suggesting that GhPME36 aggravates susceptibility to Liriomyza sativae by affecting both the structure and components of cell wall biosynthesis. Moreover, GhPME36 interacts with another pectin-modifying enzyme, GhC/VIF1, to maintain the dynamic stability of pectin methyl esterification.ConclusionsTaken together, our results reveal the cytological and molecular mechanisms by which GhPME36 aggravates susceptibility to Liriomyza sativae. This study broadens the knowledge of PME function and provides new insights into plant resistance to pests and the safety of genetically modified plants.

A Bamboo HD-Zip Transcription Factor PeHDZ72 Conferred Drought Tolerance by Promoting Sugar and Water Transport.

Drought drastically affects plant growth, development and productivity. Plants respond to drought stress by enhancing sugar accumulation and water transport. Homeodomain-leucine zipper (HD-Zip) transcription factors (TFs) participate in various aspects of plant growth and stress response. However, the internal regulatory mechanism of HD-Zips in moso bamboo (Phyllostachys edulis) remains largely unknown. In this study, we identified an HD-Zip member, PeHDZ72, which was highly expressed in bamboo shoots and roots and was induced by drought. Furthermore, PeSTP_46019, PeSWEET_23178 and PeTIP4-3 were identified as downstream genes of PeHDZ72 in moso bamboo by DAP-seq. The expressions of these three genes were all induced by drought stress. Y1H, DLR and GUS activity assays demonstrated that PeHDZ72 could bind to three types of HD-motifs in the promoters of these three genes. Overexpression of PeHDZ72 led to a remarkable enhancement in drought tolerance in transgenic rice, with significantly improved soluble sugar and sucrose contents. Meanwhile, the expressions of OsSTPs, OsSWEETs and OsTIP were all upregulated in transgenic rice under drought stress. Overall, our results indicate that drought stress might induce the expression of PeHDZ72, which in turn activated downstream genes PeSTP_46019, PeSWEET_23178 and PeTIP4-3, contributing to the improvement of cellular osmotic potential in moso bamboo in response to drought stress.