Root Production Research Articles

Response surface methodology-based optimization of hairy roots cultures for in vitro AM production

Arbuscular mycorrhizal fungi can do wonders in promoting the crop growth as well maintaining soil health. In vitro root organ culture technology is an exciting avenue for AM biofertilizer production. This study aims to optimize the key influencing factors for enhancing the hairy root production used for in vitro AMF culturing using response surface methodology, a statistical and mathematical tool used for designing optimization studies. Study uses Rhizobium rhizogenes MTCC 2364 for transformation in carrot explant. Factors considered for optimization are concentration of gelling agent (phytagel), carbon source (sucrose) and pH of the Modified Strullu and Romand medium (MSR). Design Expert software uses second order polynomial regression equation for predicting the outcome of each experiment. Totally, 17 experiments were run following Box-Behnken design and average hairy root length and average side branch emergence were taken as response. ANOVA analysis reveals that the concentration of phytagel and sucrose had a strong influence on root length, while the phytagel and pH of the medium had a strong effect on side branch emergence. Overall, taking into account the both responses, concentration of phytagel had a significant impact on hairy root production. The maximum average hairy root length obtained was 1.12 cm and number of side branches emerged were 6.78 per day. Based on these results, the optimal parameters were MSR medium with 3gL-1 phytagel, 11gL-1 sucrose and a pH of 4 for boosting hairy root development. This study is a cost-effective approach and minimizes the time taken for establishing the hairy root technology.

Photosystem rearrangements, photosynthetic efficiency, and plant growth in far red-enriched light.

Arabidopsis plants were grown in white light (400-700 nm) or in white light supplemented with far-red (FR) light peaking at 730 nm. FR-enriched light induced the typical shade avoidance syndrome characterized by enhanced length of seedling hypocotyl and leaf petiole. FR supplementation also caused a noticeable decrease in the carotenoid and chlorophyll content that was attributable to a block of pigment accumulation during plant development. The carotenoid decrease resulted from a downregulation of their biosynthesis pathway rather than carotenoid degradation. The losses of photosynthetic pigments are part of structural and functional rearrangements of the photosynthetic apparatus. The plastoquinone pool was chronically more oxidized in plants acclimated to white + FR light compared to white light-grown plants. Growth in FR-enriched light was associated with a higher photochemical efficiency of PSII compared to growth in white light and with a substantial increase in root and shoot biomass production. Light distribution between the photosystems was modified in favor of PSII by an increase in the PSII/PSI ratio and an inhibition of state transitions. Neither LHCII abundance nor nonphotochemical energy dissipation in the PSII chlorophyll antennae were modified significantly by the addition of FR light. A PSI supercomplex, not previously observed in Arabidopsis, was specifically found in plants grown in FR-enriched light. This large PSI complex contains a supplementary Lhca1-4 dimer, leading to a total of 6 LHCI antennae instead of 4 in the canonical PSI. Through those photosystem rearrangements and the synergistic interaction with white light, FR light is photosynthetically active and can boost photosynthesis and plant growth.

Root exudation of glyphosate in Eucalyptus urophylla S.T. Blake

Glyphosate stands out in the eucalyptus management, which makes it essential to know its behavior, its effects on the plant, and possible environmental impacts. This study aimed to identify and quantify the root exudation of glyphosate and aminomethylphosphonic acid (AMPA) by Eucalyptus urophylla with chromatographic and biological methods. The five glyphosate doses were tested (0, 360, 720, 1080 and 1440 g a.e ha−1) on E. urophylla plants. The physiological and intoxication evaluations were performed after herbicide application. Water samples remaining from the pots were used for chemical quantification of root exudation of glyphosate and AMPA in high-performance liquid chromatography. Cucurbita pepo plants were used as bioindicators of glyphosate in the water remaining in the pots after applying herbicide. The increase in glyphosate doses promoted linear growth in E. urophylla intoxication and significantly reduced total dry mass and root production. E. urophylla plants had their photosynthetic, transpiratory, and stomatal conductance rates reduced as the herbicide doses increased. The AMPA root exudation was not detected, but it was possible to identify the presence of glyphosate by bioassay and chemical methods. Root exudation of glyphosate by eucalyptus can result in lesser herbicide action in plant control and cause contamination of deeper soil layers.

Multi-trait selection for mean performance and stability in purple-fleshed sweet potato

Few purple-fleshed sweet potato (PFSP) cultivars are available for Brazilian growers, urging for the development of new and adapted cultivars. PFSP breeding programs should include multiple traits during the selection process to increase the chances of developing an adequate genotype, specially yield-related and quality-related traits. The objective was to select promising PFSP genotypes based on yield and tuberous-roots-related traits exploring genotype x environment interaction (GEI). Four experiments were carried out, in which 23 pre-selected PFSP genotypes were evaluated based on yield and quality traits, after screening among 2500 experimental genotypes. The first experiment adopted an augmented block design, with ‘Luiza’ interspersed as a control. From this first experiment, the 19 experimental genotypes with the best performance were selected for the following three experiments, which were conducted in a randomized block experimental design, with three replications each, including ‘Luiza’ as control. The best genotypes were selected in the first experiment using the multi-trait genotype-ideotype distance index (MGIDI). For the following experiments, the performance of the genotypes was assessed using deviance analysis, genotypic stability through weighted average of absolute scores (WAASB) index, and the multi-trait stability index (MTSI). In the first experiment, three factors were retained, being associated to commercial production of tuberous roots (‘K-104′, ‘K-25′ and ‘U1–29′), total production of tuberous roots (‘K-110′, ‘C-42′, ‘F-16′, and ‘U1–29′), and quality of tuberous roots (‘F-22′), respectively. Desired gains were observed for all traits. For the experiments II, III, and IV five factors were retained, being four related to quality of tuberous roots and one to yield components. The GEI was significant for yield-related traits and desired gains were observed for most traits. Due to high commercial tuberous root yield and low WAASB values, the genotypes ‘U1–29′, ‘K-98′, ‘F-22′, ‘K-57′, ‘C-36′, ‘U1–15′, ‘K-25′, and ‘U2–12′ were highly productive and stable. The genotypes selected by the MTSI index were ‘U1–15′, ‘U2–10′, ‘U1–29′, ‘K-98′, and ‘K-78′. The multi-trait selection enabled the identification of promising genotypes highlighting their strengths and weaknesses.

The long-term effect of biochar application to Vitis vinifera L. reduces fibrous and pioneer root production and increases their turnover rate in the upper soil layers.

Fibrous and pioneer roots are essential in the uptake and transport of water and nutrients from the soil. Their dynamic may be influenced by the changing of soil physicochemical properties due to the addition of biochar, which, in turn, has been shown to improve plant growth and productivity in the short term. However, the long-term effects of biochar application on root dynamics are still widely unknown. In this study, we aimed to investigate the long-term effects of biochar application on grapevine fibrous and pioneer root dynamics and morphological traits in relation to soil characteristics. To this aim, grapevine plants amended in 2009 and 2010 respectively with one and two doses of biochar, were analyzed in their fibrous and pioneer root production and turnover rate, standing biomass, length, and specific root length, over two growing seasons. Our findings demonstrate that in the long term, biochar application significantly increased soil pH, nutrient availability, and water-holding capacity causing a decrease in the production of fibrous and pioneer roots which is reflected in a reduction of the root web characterized though by a higher turnover rate. Furthermore, we observed that these root morpho-dynamical changes were of higher magnitude in the upper soil layers (0-20 cm) and, at least in the long term, with no significant difference between the two doses. These results suggest that in the long term, biochar can be a powerful tool for improving soil quality, which in turn lowers carbon-cost investment toward the root production and maintenance of a reduced root web that might be directed into grapevine growth and productivity. Such effects shed some light on the root plastic and functional adaptation to modified soil conditions facilitated by the long-term application of biochar, which can be used for implementing adaptive agricultural practices to face the current climate change in a frame of sustainable agricultural policies.

Heating alters the nutritional and antioxidant characteristics of lotus root

To investigate the impact of heating on the nutritional and antioxidant properties of lotus root, a comparative analysis was conducted between its heated and unheated whole powders. The whole powder of heated lotus root (HLRWP) exhibited a higher level of total soluble sugars but a lower level of free phenolic compounds compared to the whole powder of fresh lotus root (FLRWP). Meanwhile, they showed significant differences in metabolite composition encompassing phenolic compounds, flavonoids, amino acids, vitamins and lipids. The replacement of sugar and corn in the medium with 25% HLRWP effectively enhanced the activities of antioxidant enzymes (total superoxide dismutase and catalase), while reducing malonaldehyde content in Drosophila melanogaster males. The average, median and maximum lifespans of the fruit flies were extended by 35.90%, 23.49% and 24.00% respectively, accompanied by an improvement in climbing ability. Additionally, their resistance to oxidative stress induced by hydrogen peroxide or paraquat was enhanced. The antioxidant capacity of HLRWP in vivo was found to be obviously stronger compared to FLRWP, which may have a crucial association with the regulation of L-arginine and adenosine monophosphate levels. The results indicate that heating can enhance the nutritional quality of lotus root products by strengthening their antioxidant capacity.

Isolation, selection and identification of lactic bacteria from pickled salt lotus root in Giang Thanh district, Kien Giang province

The study was conducted to isolate, select, and identify the lactic acid bacteria strain with the highest lactic acid fermentation ability from pickled lotus root products in Giang Thanh district, Kien Giang province. From three samples of pickled lotus root collected in Giang Thanh district, 11 lactic acid bacteria strains were isolated and preliminarily identified through colony morphology and some biochemical reactions such as Gram staining and catalase reaction. The results of determining the fermentation type showed that all 11 isolated bacterial strains had a homomorphic fermentation type, the main fermentation product was lactic acid. Of which, strain D15 had the highest lactic acid content, reaching 1.87 mg/mL and had the highest biomass growth ability, with an OD600nm value of 0.947. The 16S rRNA gene sequence of strain D15 was determined with a molecular size of 1469 bp. Comparing the 16S rRNA gene sequence of strain D15 on the gene bank, it has a similarity level of 100% with some lactic acid bacteria strains of the species Lactobacillus plantarum and 99.68% when comparing with the 16S rRNA gene sequence of the standard strain Lactobacillus plantarum. Constructing a phylogenetic tree and evaluating the genetic relationship of strain D15, the standard strain Lactobacillus plantarum, and 9 strains with the highest similarity to strain D15 based on the 16S rRNA gene sequence. The results were classified into 2 large groups with a similarity level of 92%, in which strain D15 is in the same group as the standard strain Lactobacillus plantarum and also has a similarity level of 92%.

Water and Irrigation Needs of Tuber Crops in Coastal Climates: A Review

One of the most essential elements for plant growth is water. Large amounts of it are required by plants constantly throughout their life cycle. It significantly affects agricultural activities like irrigation, soil management, crop production, and chemical spraying environments, as well as plant processes like photosynthesis, respiration, absorption, transport, and use of mineral nutrients. This review examines the impacts of climate change on root and tuber crops, including rising temperatures, altered rainfall patterns, extreme weather events, and changes in pest and disease dynamics. These changes significantly affect root and tuber crop production, leading to lower yields, compromised quality, increased susceptibility to pests and diseases, and limited access to water resources. Adaptation strategies encompass various approaches, such as agronomic practices, crop diversification, improved water management, breeding for climate resilience, and agro ecological methods. In the world, the most significant root and tuber crops are cassava, sweet potatoes, and potatoes. Water will produce maximum production for root crops; however, water stress during critical stages might adversely affect the final output of root crops. The purpose of this article of review is to understand the water and irrigation needs of tuber crops (sweet potato, greater and lesser yams, aerial yams, elephant foot yams, xanthosoma, and cassava) that are effectively produced in Maharashtra's coastal climate. This review emphasizes the urgent need to address climate change impacts on tropical root and tuber crops. It highlights the critical role of adaptive measures in ensuring long-term sustainability and food security in a changing climate.

Seasonal and interspecific variations in the water uptake depth of trees in a moist cool-temperate mixed forest in Japan

ABSTRACT The water uptake depth of trees affects their overall water use and the water cycle of forest ecosystems. However, empirical data on the depth from which water is drawn are lacking for many moist forests. In this study, we estimated the water uptake depths of 24 coexisting tree species in a moist cool-temperate mixed forest in Japan using stable oxygen isotopes. Our goal was to clarify the factors influencing water uptake depth including season, species, slope position, and tree height under moist conditions. Water uptake depth was determined during three periods in which temperatures differed but soil moisture levels remained similar. Season was shown as one of the factors affecting water uptake depth, which was shallowest in August, when temperatures reached maximum values, and deepest during May, when temperatures were lowest. This seasonal variation is likely to be related to physiological processes such as increasing transpiration which leads to water uptake shifting to the water-rich shallow soil layer and/or activation of fine root production at the soil surface, where temperatures are high. Water uptake depth also varied with tree species, suggesting the occurrence of belowground resource segregation among moist forest tree species. Slope position and tree height did not affect water uptake depth. This study highlights the importance of considering temperature-driven physiological processes when examining water uptake depth in moist forests, which could have implications for predicting the responses of these ecosystems to climate change.

Utilizing bioformulation to increase root colonization, soil fertility, and productivity of chilli (Capsicum annuum L.)

Utilizing bioformulation to increase root colonization, soil fertility, and productivity of chilli (Capsicum annuum L.)

Effects of a Prophylactic Treatment with Horseradish Root and Nasturtium Herb on Urinary Tract Infections in Individuals with Chronic Neurogenic Lower Urinary Tract Dysfunction: A Retrospective Cohort Study

Introduction: Recurrent urinary tract infections (UTIs) are common in individuals with neurogenic lower urinary tract dysfunction (NLUTD) and greatly affect their quality of life. There is currently no established prophylactic measure based on evidence. We have therefore evaluated the effects of a horseradish root and nasturtium herb product on the frequency of UTIs in a retrospective cohort. Methods: Clinical data of patients with chronic NLUTD who were receiving the phytotherapeuticum for at least 12 months were analyzed. The number of UTIs was categorized as no UTIs, sporadic UTIs (1–2/year) and recurrent UTIs (≥3/year). The change in the annual number of patient-reported symptomatic UTIs and antibiotic prescriptions was investigated. Results: Data of 43 individuals (mean age 49 ± 13 years, median NLUTD duration 17.9 years) were analyzed. The proportion of individuals with recurrent UTIs decreased significantly (p < 0.0001) from 58.1% (42.1–73.0%) to 23.3% (11.8–38.6%) during phytotherapy, whereas the proportion of individuals without UTIs increased significantly (p = 0.001) from 14.0% (5.3–27.9%) to 39.5% (25.0–55.6%). In addition, there was a significant (p = 0.008) decrease in the number of antibiotic prescriptions. Conclusion: Prophylactic treatment with horseradish root and nasturtium herb seems to be a promising option for the prevention of UTIs.

Effects of different timing and rate of glyphosate application on the residue level, grain quality, and processing performance of two Canadian malting barley varieties

AbstractBackground and ObjectivesA preharvest application of glyphosate on malting barley can assist in the management of perennial weed growth before harvest and serves as a harvest aid by drying down the crop. The main objective of this study was to assess the effects of preharvest glyphosate application at two glyphosate rates (900 or 1125 g ae/ha) and three application timings based on the maturity and seed moisture level (soft dough, hard dough, or mature).FindingsThe levels of glyphosate residue in barley grain were highly variable among locations and years ranging from 0 to 95 mg/kg. Glyphosate application at both rates at the soft dough stage significantly decreased the kernel weight of barley grain. Barley grain with up to 40 mg/kg of glyphosate residue exhibited adequate germination energy required for malting purposes; however, the residue negatively affected the growth of roots during the malting process. The levels of α‐amylase in malt decreased with increasing levels of glyphosate residue in barley. Other malt and wort parameters were generally not affected by the glyphosate application on barley.ConclusionsToo early application of glyphosate at the soft dough stage of barley grain development reduced the kernel weight and size, interfered with roots production, affected synthesis of α‐amylase, and reduced the malt extract in several cases.Significance and NoveltyResults indicated that in the majority of environments, when glyphosate was applied at the recommended stage and rate, neither the maximum residue limit was exceeded nor were the germination and malting quality of barley impaired. In real farming conditions, it might be hard to achieve similar results despite adherence to the recommended timing of glyphosate application because of the nonuniform level of crop maturity in the field and/or uncontrollable environmental effects.

Fine Roots in Hemiboreal Forest Stands and Clearcut Areas with Nutrient-Rich Organic Soils in Latvia: Morphological Traits, Production and Carbon Input

Within this study, we evaluated the fine root (trees and understory vegetation combined) morphological traits, fine root production (FRP), and carbon (C) input with fine root litter in forest stands (dominated by either coniferous or deciduous trees) and clearcut areas (previously dominated by coniferous trees) with nutrient-rich organic soils. The study was conducted in 26 sites in hemiboreal forest land in Latvia and summarizes the results obtained in a two-year study (2020–2022) using the root ingrowth method. Traits and production of fine roots varied significantly depending on forest development stage (stand or clearcut area), dominant tree species type (coniferous or deciduous), and soil drainage status (drained or naturally wet). According to the results of the second study year, mean FRP among groups of study sites varied from 0.58 ± 0.13 to 1.38 ± 0.28 t ha−1 yr−1, while C input with fine root litter ranged from 0.28 ± 0.06 to 0.68 ± 0.14 t C ha−1 yr−1. More than half (59 ± 4%) of the total FRP occurred in the upper 0–20 cm soil layer. FRP tended to correlate positively with soil C/N ratio and negatively with soil pH and soil nutrient concentration. Incubating ingrowth cores for at least two years is strongly recommended to accurately estimate annual FRP and C input. This helps to avoid potential underestimation that may occur when using results of only one incubation year (12 months after ingrowth core installation). This study provided new insights into the dynamics and traits of fine roots and will help to improve the accuracy of C flow estimation in hemiboreal forests with nutrient-rich organic soils in Latvia.

Effects of application methods of microbial mixture on early blight disease (Alternaria solani) and growth of potato

Early blight (Alternaria solani) is one of important diseases in potato in Indonesia. In previous study, a microbial consortium (Trichoderma harzianum, Bacillus subtilis and Pseudomonas sp.) suppressed the bacterial wilt disease in potato. For application, the microbial consortium was mixed with compost (10%). As the microbial consortium is originally intended for controlling soil-borne diseases, this study examined the ability of the microbial consortium to suppress early blight disease and the effects of application methods on its efficacy. The application methods examined were the methods that targeted for soil-borne as well as airborne diseases. The experiment was conducted in a greenhouse at the Department of Plants and Diseases, Faculty of Agriculture, Universitas Padjadjaran, Sumedang, West Java, Indonesia. The experiment used Randomized Complete Block Design with 10 treatments and three replications. The treatments included application of microbes mixed with compost in planting hole solely or in combination with soaking the potato tubers in suspension of the microbes, drenching water extract of the mixture at 2, 4, 6 weeks after planting (WAP) with or without foliar application of the water extract. The result showed that application method influenced the abilities of the microbial mixture in suppressing early blight disease and supporting the potato growth. Even though the application of microbe-compost in planting medium inhibited the development of early blight disease by 37.8-39.5%, the regular foliar spray of the water extract of the mixture enhanced the disease suppression. Combination between application of the microbe-compost in the planting hole, drenching its water extract at 2, 4, 6 WAP and weekly foliar spray of the water extract suppressed early blight disease by 80.8%. This combination of application methods also supported better plant height, numbers of potato leaflets, roots fresh weight and production of potato tuber.

Phosphorus application under continuous wheat-cotton straw retention enhanced cotton root productivity and seedcotton yield by improving the carbohydrate metabolism of root

ContextStraw retention could reduce phosphorus (P) application without decreasing seedcotton yield but related physiological mechanisms were unclear. Cotton root is the first organ to sense the changes in soil environment, and its growth and development, especially carbohydrate metabolism, significantly affected the formation of seedcotton yield. Therefore, it is necessary to explore the responses of cotton root carbohydrate metabolism to straw retention combined with P application. ObjectiveThis study was to investigate the effects of straw retention combined with P application on root carbohydrate metabolism and its relationship with seedcotton yield. MethodsA field experiment (2020–2022) was conducted to evaluate the changes in seedcotton yield, cotton canopy apparent photosynthesis rate (CAP), biomass, root productivity, root carbohydrate contents and related enzyme activities under different straw management [removal (S0), retention (S1)] and P rates (0, 100, 200 kg P2O5 ha−1). ResultsStraw retention and P application both increased seedcotton yield and had a significant interaction effect on it. In the 5th-7th year of straw retention, straw retention reduced 24 %-26 % P application to reach a similar yield of S0 with 100 kg P2O5 ha−1. Analyzing the reasons: (1) Straw retention combined with P application increased cotton CAP, providing adequate assimilates for cotton development; (2) Straw retention combined with P application promoted the utilization of root carbohydrates, thereby increasing root productivity and seedcotton yield. Specifically, compared with S0 without P, S1 combined with P application increased the enzyme activities related to carbohydrate metabolism, especially sucrose synthase (7.6 %-59.4 %) and acid invertase (3.9 %-58.6 %), which reduced sucrose (3.3 %-32.2 %) and starch (4.3 %-28.7 %) contents at the peak boll setting stage. Efficient utilization of sucrose and starch enhanced root productivity, the ratio of root to shoot (R/S) reduced by 2.7 %-21.6 %, while the boll loading of root system (BLR) and boll capacity of root system (BCR) increased by 0.6 %-39.2 % and 3.1 %-50.6 % at the boll opening stage, respectively, favoring the formation of seedcotton yield. Furthermore, when the R/S, BLR, and BCR reached 0.12, 0.81 boll g−1, and 4.33 g g−1, cotton harvested the maximum theoretical yield of 3780, 3774, and 4069 kg ha−1, respectively. ConclusionsStraw retention combined with P application increased root productivity and seedcotton yield by promoting the utilization of root carbohydrates. ImplicationsThis study revealed the internal mechanism for straw retention combined with P application to affect seedcotton yield from the angle of root carbohydrate metabolism and provided a theoretical basis for rationally reducing P fertilizer under straw retention.

Ameliorating the detrimental effects of chromium in wheat by silicon nanoparticles and its enriched biochar

Increased anthropogenic activities over the last decades have led to a gradual increase in chromium (Cr) content in the soil, which, due to its high mobility in soil, makes Cr accumulation in plants a serious threat to the health of animals and humans. The present study investigated the ameliorative effect of foliar-applied Si nanoparticles (SiF) and soil-applied SiNPs enriched biochar (SiBc) on the growth of wheat in Cr-polluted soil (CPS). Two levels of CPS were prepared, including 12.5 % and 25 % by adding Cr-polluted wastewater in the soil as soil 1 (S1) and soil 2 (S2), respectively for the pot experiment with a duration of 40 days. Cr stress significantly reduced wheat growth, however, combined application of SiF and SiBc improved root and shoot biomass production under Cr stress by (i) reducing Cr accumulation, (ii) increasing activities of antioxidant enzymes (ascorbate peroxidase and catalase), and (iii) increasing protein and total phenolic contents in both root and shoot respectively. Nonetheless, separate applications of SiF and SiBc effectively reduced Cr toxicity in shoot and root respectively, indicating a tissue-specific regulation of wheat growth under Cr. Later, the Langmuir and Freundlich adsorption isotherm analysis showed a maximum soil Cr adsorption capacity ∼ Q(max) of 40.6 mg g−1 and 59 mg g−1 at S1 and S2 respectively, while the life cycle impact assessment showed scores of −1 mg kg−1 and -211 mg kg−1 for Cr in agricultural soil and − 0.184 and − 38.7 for human health at S1 and S2 respectively in response to combined SiF + SiBC application, thus indicating the environment implication of Si nanoparticles and its biochar in ameliorating Cr toxicity in different environmental perspectives.

Joint analysis of land, carbon and nitrogen reveals diverging trends in the sustainability of organic crops in Spain

The world's top ten Organic Farming (OF) countries by converted area include several Mediterranean countries, including Spain. Despite this, little is known about the consequences of OF on crop production and environmental sustainability in this country. In this article, we conduct an agronomic analysis of Spanish considerable conversion rate to OF, which tends to concentrate in certain provinces and crops. Indeed, in the case of various crops and in several provinces, the organic share of total agricultural land exceeds 20–30 %. This concentration makes it possible to compare information obtained from farmers through interviews and provincial statistical information. The study data consisted of information collected from interviews of a representative sample of organic farmers conducted in 2004 and 2020 as well as official statistical information. The results showed that no yield gap between OF and conventional farming was found for vegetables and fruit trees, while it showed an increasing trend in arable crops. Presumably, the reason is that fruit trees and vegetables generate and incorporate high levels of carbon (C) flows into the soil and have a low land cost per unit of incorporated nitrogen (N) (or can be paid for), allowing to meet crop needs and to increase soil organic matter (SOM). Conversely, in the case of rainfed arable crops, the soil C and N inputs are deficient due to the low crop residues and the high land cost of N. Consequently, SOM destruction and N deficit progressively broaden the yield gap, undermining the agroecosystem sustainability. To reverse the situation, among other measures, it is necessary to implement agricultural policies designed to make rotations with high legume ratios viable and to plant varieties presenting higher production of residues and roots, such as traditional varieties.

Agrobacterium transformation of Rhodiola sp.: current status and limitations

The study of secondary metabolites has led to the discovery of new drugs for treating human diseases. However, consistent plant supply can be challenging, leading to the use of plant tissue culture techniques such as hairy root culture. Hairy roots have stable genetics, lateral branching, and can produce secondary metabolites, including alkaloids, flavonoids, and terpenoids. Research on hairy roots as a subject began in the late 19th century, and for the last four decades, hairy roots have been utilized for producing secondary metabolites and recombinant proteins. This article focuses on Rhodiola species - genus of perennial plants that belongs to the family Crassulaceae - and its potential as a source of secondary metabolites using hairy root culture techniques. Rhodiola sp. is widely distributed throughout the Arctic regions of the Northern Hemisphere, with several species having significant medicinal properties. The article discusses the possible use of hairy root cultures for the production of Rhodiola secondary metabolites, including salidroside and rosavins, which have demonstrated significant pharmacological activity in various studies. The use of elicitation and genetic engineering techniques to boost secondary metabolite production in Rhodiola hairy roots is also explored. Overall, the article highlights the potential of Rhodiola hairy root cultures as a valuable source of secondary metabolites with medicinal properties. However, despite some studies Rhodiola hairy root induction and culturing still remains highly unexplored.

Effects of Warming and Increased Precipitation on Root Production and Turnover of Stipa breviflora Community in Desert Steppe

Effects of Warming and Increased Precipitation on Root Production and Turnover of Stipa breviflora Community in Desert Steppe

Differential response of roots and leaves to combined heat and salinity stresses in tomato plants

Despite our understanding of plant responses to single stresses, knowledge on how plants respond to combined abiotic factors and the underlying hormonal regulation is still very limited. Here, we aimed to examine the plant response to combined heat and salt stresses in tomato plants, the underlying hormonal response and the effectiveness of methyl jasmonate application in its alleviation. We measured fruit production and various stress markers in both roots and leaves, together with endogenous contents of stress-related phytohormones (including abscisic acid, salicylic acid and jasmonates) in tomato plants (Solanum lycopersicum cv. Micro-Tom), exposed to combined stress. In addition, we evaluated the effectiveness of a methyl jasmonate treatment as a priming agent to alleviate the negative effects of stress, with an emphasis on evaluating the effects of this hormone on triggering antioxidant protection by enhancement of vitamin E contents. Plants responded differently to combined stress treatment than to single stresses, but this differential response was organ-specific, with roots being more sensitive to stress than leaves. Both abscisic acid and jasmonates were involved in the plant response to combined stress but leaves and roots responded differently. Furthermore, abscisic acid and jasmonates correlated with vitamin E accumulation, most particularly in roots. Foliar application of methyl jasmonate at the flowering stage in plants challenged with combined stress did not improve fruit production but resulted in enhanced vitamin E accumulation in leaves. It is concluded that (i) roots and leaves show a differential sensitivity to both single and combined heat and salt stresses, (ii) the response of abscisic acid and jasmonates in plant stress responses seems to be markedly organ dependent, and (iii) foliar methyl jasmonate increased vitamin E accumulation under combined stress in tomato plants.