Regulatory Substances Research Articles

Pengaruh Jenis Zat Pengatur Tumbuh terhadap Pertumbuhan Awal Bibit Sengon Laut (Paraserianthes falcataria)

Growth Regulatory Substances stimulate growth by signaling target cells to divide, grow or inhibit cell division or elongation. Plant response to ZPT application varies greatly depending on the stage of development. The growth of shoots and roots can be stimulated by immersing ZPT, because this method makes it easier for a part of the sengon plant, namely the seed, to absorb growth regulators. This study aims to determine the effect of the type of growth regulator on the initial growth of sea sengon seedlings. This research was conducted at the Jember State Polytechnic from June 2022 to September 2022. This study used a Non-factorial Randomized Block Design consisting of 4 levels, namely ZPT gibrelin acid (50 ppm), antonic (2 cc), coconut water 1 liters and finally water (control). Each treatment combination was repeated 6 times. The obtained data were analyzed using ANOVA at the 5% level. Has the result that the treatment of giving the type of growth regulator treatment on the initial growth of sea sengon seedlings has a significant effect on plant height (cm) and germination ability, and has no significant effect on stem diameter (mm), number of petioles, root length (cm), weight plant wet weight (grams), plant dry weight (grams), root wet weight (grams) and root dry weight (grams).

The effect of various natural growth regulatory substances and the origin of stem cuttings on the vegetative growth of white jasmine (Jasminum sambac L.)

Jasmine is a native plant of the archipelago in Indonesia. Jasmine (Jasminum sambac L.) is a plant that has many ingredients, including as an ornamental plant, the chemical content of jasmine flowers, namely indole, benzyl, livalyacetat, is believed to be able to treat diseases such as headaches, shortness of breath, fever, excess breast milk and eye pain. Shallot extract is one of the natural growth regulators, namely the auxin group which contains indole and naphthalene compounds which function to stimulate the development of adventitious root meristems. Bean sprouts are one type of vegetable that is commonly used for consumption, easy to obtain, has economic value, and does not have toxic compounds. Bean sprout extract contains growth regulators, namely auxins and cytokinins. Based on the research results, it was found that the concentrations of various natural growth regulators were significantly different with respect to the number of shoots, shoot length, and number of leaves. The best treatment of natural growth regulators was found in shallot extract 50% (Z2). The type of cutting material differed significantly with the number of shoots, shoot length, and number of leaves. The best cutting material treatment was found in the middle of the branch (B2).

The effect of varieties of true shallot seed and paclobutrazol concentrations on growth and production of shallot plant

The increasing demand for shallots is inversely proportional to the quality of the current production. Efforts to improve and increase quality of production are selection of good varieties and add plant regulatory substances has also become the focus of many researchers in their effect on plant growth. Therefore, research was carried out on the effect of the varieties and also plant regulatory substances namely paclobutrazol on the growth and production of shallot plants. This research was carried out at the Teaching Farm, Faculty of Agriculture, Hasanuddin University from August to November 2021. This research was carried out as a factorial experiment in a split plot design, as the main plot, namely the botanical seed varieties of shallot (v) consists of 3 varieties, namely the Lokananta varieties (v1), Maserati varieties (v2), and Sanren varieties (v3), as a sub-plot, namely the concentration of paclobutrazol consists of 4 levels, namely 0 ppm (k0), 100 ppm (k1), 200 ppm (k2) and 300 ppm (k3). The research results showed that the interaction of the Sanren varieties with paclobutrazol concentration of 100 ppm gave the best results on the weight of fresh stover per plant (26.04 g), weight of dry stover per plant (19.23 g) and production per hectare (9.20 ton/ha). The Sanren varieties gave the best results on chlorophyll a (387.23 μmol.m−2), chlorophyll b (187.12 μmol.m−2), total chlorophyll (564.14 μmol.m−2) and number of tubers (1.81). Paclobutrazol concentration of 100 ppm gave the best results on plant height (43.07 cm) and number of leaves (6.24 strands), while paclobutrazol concentration of 200 ppm gave the best results on tuber diameter (23.13 mm) and paclobutrazol concentration of 300 ppm gave the best results on the number of tubers (1.54).

The utilization of atonic growth regulatory substances and shallot extract on the growth of sago seeds (metroxylon sagu rottb.)

This study aims to determine and obtain recommendations for the treatment of growth regulators that are appropriate for the growth and development of sago seeds at the nursery stage. The research was conducted in Pengkajoang Village, West Malangke District, North Luwu Regency from May 2022 - July 2022. The sago seeds used in this study were non-thorny types of sago seeds. Parameters observed in this study include the percentage of live seedlings and petiole length. Data obtained from observations were analyzed using ANOVA. The results showed that the shallot extract treatment of 500 ml/Liter had a better average percentage of live seedlings and petiole length, namely 26.7% and 9.6 cm. Meanwhile, the combination treatment of shallot extract and atonic growth regulator 1000 ml/liter had the lowest average on the observed parameters.

Study on the effect of growth regulators and the concentration of coconut water on the growth and yield of garlic shallots (Allium ascalonicum L.)

An investigation on the influence of Atonic Growth Regulatory Substances and coconut water immersion on the growth and yield of shallots was conducted from March 3 to May 9 in 2023, in Tawangrejo Village, Ngrambe, Ngawi. The objective of this study is to analyze the impact of different doses of ZPT Atonik and coconut water on the growth and yield of shallots (Allium ascalonicum L). The experiment was designed using a Completely Randomized Block Design (RAKL), which included two factorials. The first factorial was the level of coconut water immersion concentration (K), consisting of four levels, namely K0 = 0%, K1 = 80%, K2 = 90%, and K3 = 100%. The second factor in this study is Atonik (A), which consists of four levels: A1 = 0 ml/l, A1 = 1.5 ml/l, A2 = 3.0 ml/l, and A3 = 4.5 ml/l. Each experiment in this study will be repeated three times and comprise four treatment levels, resulting in a total of 16 treatment combinations. We analyzed the data using Analysis of Variety followed by the Honest Significant Difference Test (BNJ) at the 5% level. The study results revealed that the Atonik treatment and coconut water immersion did not have a significant effect on the observed parameters of the number of leaves (40.30), number of tubers (17.87), tuber diameter (2.45 cm), fresh weight (130.63 g), and dry weight (109.22 g), but had a significant effect on the observed parameter of plant height (41.33 cm).

ROS-mediated waterlogging memory, induced by priming, mitigates photosynthesis inhibition in tomato under waterlogging stress.

With global climate change, the frequency and intensity of waterlogging events are increasing due to frequent and heavy precipitation. Little is known however about the response of plants to repeated waterlogging stress events. The aim is to clarify physiological regulation mechanisms of tomato plants under repeated waterlogging stress, and whether Trichoderma harzianum can alleviate waterlogging injury. We identified two genotypes of tomato, 'MIX-002' and 'LA4440', as waterlogging tolerant and sensitive genotypes, respectively, based on plant biomass accumulation. The two tomato genotypes were subjected to a waterlogging priming treatment for 2 days (excess water for 1cm above substrate surface) followed by a recovery stage for 2 days, and then a second waterlogging stress for 5 days (excess water for 1cm above substrate surface) followed by a second recovery stage for 3 days. Leaf physiological, plant growth parameters, and the expression of five key genes were investigated. We found that the two genotypes responded differently to waterlogging priming and stress in terms of photosynthesis, reactive oxygen species (ROS), and osmotic regulatory mechanisms. Waterlogging stress significantly increased H2O2 content of 'MIX-002', while that of 'LA4440' had no significant change. Under waterlogging stress, photosynthesis of the two genotypes treated with waterlogging priming returned to the control level. However, Trichoderma harzianum treatment during the second recovery stage did not show positive mitigative effects. The plants of 'LA4440' with priming showed lower peroxidase (POD) activity and proline content but higher H2O2 content than that without priming under waterlogging stress. Under waterlogging stress with priming as compared to without priming, SODCC2 was downregulated in two tomatoes, and AGR2 and X92888 were upregulated in 'MIX-002' but downregulated in 'LA4440'. Overall, the two tomato genotypes exhibited distinct photosynthetic, ROS and osmotic regulatory mechanisms responding to the waterlogging stress. Waterlogging priming can induce stress memory by adjusting stomatal conductance, sustaining ROS homeostasis, regulating osmotic regulatory substances and key gene expressions mediated by H2O2, and thus alleviate the damage on tomato photosynthesis when waterlogging reoccurred.

Brassinosteroids Regulate the Water Deficit and Latex Yield of Rubber Trees.

Brassinolide (BR) is an important plant hormone that regulates the growth and development of plants and the formation of yield. The yield and quality of latex from Hevea brasiliensis are regulated by phytohormones. The understanding of gene network regulation mechanism of latex formation in rubber trees is still very limited. In this research, the rubber tree variety CATAS73397 was selected to analyze the relationship between BR, water deficit resistance, and latex yield. The results showed that BR improves the vitality of rubber trees under water deficit by increasing the rate of photosynthesis, reducing the seepage of osmotic regulatory substances, increasing the synthesis of energy substances, and improving the antioxidant system. Furthermore, BR increased the yield and quality of latex by reducing the plugging index and elevating the lutoid bursting index without decreasing mercaptan, sucrose, and inorganic phosphorus. This was confirmed by an increased expression of genes related to latex flow. RNA-seq analysis further indicated that DEG encoded proteins were enriched in the MAPK signaling pathway, plant hormone signal transduction and sucrose metabolism. Phytohormone content displayed significant differences, in that trans-Zeatin, ethylene, salicylic acid, kinetin, and cytokinin were induced by BR, whereas auxin, abscisic acid, and gibberellin were not. In summary, the current research lays a foundation for comprehending the molecular mechanism of latex formation in rubber trees and explores the potential candidate genes involved in natural rubber biosynthesis to provide useful information for further research in relevant areas.

The Effect Of ZPT Types and Concentration on The Growth Of Kebiul Plant Cuttings (Caesalpinia bonduc L.)

The purpose of this study is to find out the effect of ZPT types and concentrations on the growth of cuttings of Kebiul plants (Caesalpinia bonduc L). The design used is a factorial complete randomized design (CRD) with 2 factors, namely the first factor is the type of Growth Regulatory Substance Giberelin, Auxin and Cytokinins, while the second is concentration control, 15 mg/l, 30 mg/l, and 45mg/l. Based on the tested levels of the two factors, 12 treatment combinations were obtained. Each treatment combination was repeated 3 times and 36 experimental units. The results of this study indicate that the interaction has no significant effect between the types of synthetic ZPT treatments and concentrations on all parameters and observations. The results of the study were analyzed using Analysis of Variety and if they had a significant effect, further tests were carried out using Duncan's Multiple Range Test (DMRT) at 5% level. Treatment of synthetic ZPT types significantly affected the length of shoots 9.12 WAP and the number of shoots 9 WAP, very significantly affected the number of shoots 3.12 MST, the number of leaves 9.12 WAP, root length and number of roots. Treatment Concentration had a significant effect on the number of shoots 9 MST, and the percentage of living cuttings, however it had a very significant effect on shoot length 3, 6, 9 MST, number of shoots 6, 12 MST, number of leaves 3, 6, 9 12 MST, root length and number of roots on Kebiul plant cuttings.

Literature Review : Pengaruh Gizi dan Kesehatan terhadap Pertumbuhan dan Perkembangan pada Anak

Children are the future of the nation and state because they are the next generation. So that children can grow and develop normally, the role of nutrition is very vital and must be considered. With the fulfillment of nutritional needs, such as carbohydrates as a source of energy (energy), protein as a builder substance and vitamins/minerals as a regulatory substance. will help prevent disease. This results in stunted growth and development of children. Growth and development will be assisted by the proper nutritional composition; healthy food is food that is adjusted to the activity level and age of consumers. This is so that by fulfilling nutritional needs, the components of maintenance, growth, repair of damaged/worn/lost bodies, and reproduction of physical energy can be carried out entirely. Objektif: The benefits of balanced nutrition in children can make their body, intelligence, and abilities develop properly. rapidly. Physically, with good nutrition, children will be healthier and not get sick easily. Methods: The method used is the study of literature from various international and national journals, with a descriptive analysis approach. Results: The results showed that there was a positive relationship with strong strength and statistically significant between growth stimulation and child development. Conclusion: Nutrition is an important factor in the process of physical growth and development of children who are growing and developing. The nutrients needed include breast milk (ASI), energy, prolein, fat, carbohydrates/carbohydrates, vitamins and minerals. In providing nutrients, it is hoped that it will be in accordance with a balanced menu and large portions adjusted to the child's acceptability

Daya Kecambah Benih Rotan Jernang (Daemonorops draco Blume) dengan Perlakuan Perendaman Zat Pengatur Tumbuh Atonik

Good germination of rattan jernang (Daemonorops draco Blume) seeds will increase germination power, germination rate, and germination value. However, there are still obstacles to germination, because the jernang rattan seeds have a dormancy period. Soaking in Atonic Growth Regulatory Substances (ZPT) is one method that can be used to break thedormancy period of seeds. This study aims to determine the dose and soaking time on the germination value of jernang rattan seeds (D. draco Blume). The study used four treatments and 3 groups/replications. The treatment in this study was the dose of ZPT Atonik, namely 50 CC/Liter, 80 CC/liter, 120 CC/liter, 150 CC/liter. Grouped by immersion time, 24 hours, 48 ​​hours and 72 hours. The results showed that the best germination percentage of German rattan (D.draco Blume) seeds were treated with ZPT Atonik dose of 120 cc/liter and soaked for 48 hours with a percentage of 100%. The best seed germination rate was at 150CC/liter treatment and 24 hours of soaking time, which was 50%/day. The highest germination value was found in seeds treated with ZPT 120CC/liter and soaking for 48 hours with an average of 0.0036%/ day. The conclusion of this study is that the ZPT Atonik dose of 120 CC/liter and 48 hours of soaking time has an effect on the percentage of germination power and germination value, while the ZPT dose of 150 CC/liter with 24 hours of soaking time increases the germination rate

RESPON STEK CABANG BAMBU BETUNG (Dendrocalamus asper) TERHADAP PEMBERIAN ZPT ALAMI

Betung bamboo is widely used for building construction materials, furniture, and has ecological benefits because it is hard and strong. Bamboo propagation can be done generatively and vegetatively. Generative propagation has weaknesses, namely bamboo seeds are very difficult to obtain, seed viability is low, seeds cannot be stored for long, are susceptible to pests and diseases, and require a very long time to reach the age of the first harvest. Regulatory substances that can be used to encourage the growth of bamboo branch cuttings are shallots and banana weevils. The study was arranged in a completely randomized design (CRD) with 9 treatments namely A0 (control), A1 (25% banana weevil), A2 (50% banana weevil), A3 (75% banana weevil). banana), A4 (100% banana weevil), A5 (25% shallot), A6 (50% shallot), A7 (75% shallot), A8 (100% shallot). The results showed that natural ZPT (banana and shallot weevils) had no significant effect on the growth of betung bamboo branch cuttings. Although no treatment had a significant effect, when viewed from the average value of each parameter, it can be said that the treatment of natural ZPT concentrations on bamboo betung branch cuttings was in treatment A8 (100% shallot concentration) for the parameter of the period of shoot emergence, treatment A6 (50% shallot concentration) for the number of leaves parameter, treatment A0 (control) for the root length parameter and for the parameter living percentage of bamboo betung branch cuttings showed the highest average for all treatments.

Foliar water uptake and its influencing factors differ between female and male Populus euphratica

In arid ecosystems, foliar water uptake (FWU) plays an important role in improving plant physiological performance. However, the structural and physiological response mechanism of FWU between male and female woody desert plants has not been reported. Using the dioecious desert woody plant Populus euphratica, the current study explored the structural and physiological response mechanism of male and female P. euphratica leaves to water absorption via an FWU capacity experiment based on leaf epidermal cell wall components and cell structure, osmotic adjustment, and oxidative metabolism indicators. The results showed that both male and female P. euphratica plants could absorb water through leaves. The per unit area of leaf water absorption (AFWU) and the leaf absorption speed (k) of female P. euphratica were higher than those of male P. euphratica, and the TFWU was approximately twice that of male P. euphratica. The leaf thickness (LT), palisade tissue thickness (TP) and the contents of cellulose and pectin of female were significantly larger than those of male P. euphratica. The contents of sucrose, glucose, soluble sugar, proline and peroxidase in female leaves were significantly higher than those in male leaves. Multivariate factor analysis showed that the AFWU of the leaves was strongly correlated with glucose, cellulose, TP, and catalase, and the k was strongly correlated with starch, pectin, LT, and malondialdehyde. The FWU capacity of female P. euphratica was stronger than that of male P. euphratica, which was caused by the difference in cell structure and osmotic regulatory substances. These results provide a new perspective for understanding the water utilization mechanism reproduction strategy of dioecious plants.

Kesehatan Diri Dan Lingkungan : Pentingnya Gizi Bagi Perkembangan Anak

Children are the next generation and are the foundation of the future for the nation and state. With the promotion of human resources at this time, children are also one of the targets of HR. In order for children to grow and develop normally, the role of nutrition is very necessary and must be considered. By fulfilling nutritional needs, such as carbohydrates as a source of energy (energy), protein as a building agent and vitamins/minerals as a regulatory substance, it will help prevent disease. which results in inhibiting the growth and development of children. Proper nutritional composition will spur growth and development, good food is food that is adjusted to the age level and type of activity. With the fulfillment of nutritional needs, it is hoped that the elements of maintenance, growth, repair of damaged or lost bodies, reproduction, physical work and Specific Dynamic Action (SDA) will also be good.

Effects of elevated CO2 concentration on cell structure and stress resistance physiology of Setaria italica under drought stress.

The frequency of drought will increase under further warming. The increase in atmospheric CO2 concentration, along with more frequent drought, will affect crop growth. We examined the changes of cell structure, photosynthetic physiology, antioxidant enzymes, osmotic regulatory substances, and yield of foxtail millet (Setaria ita-lica) leaves under different CO2 concentrations (ambient air CO2 concentration and ambient atmospheric CO2 concentration + 200 μmol·mol-1) and water treatment (soil moisture content maintained at 45%-55%, and 70%-80% of field capacity, representing mild drought and normal water condition, respectively). The results showed that elevated CO2 concentration increased the number of starch grains, the area of single starch grains, and the total area of starch grains in the chloroplast of millet mesophyll cells. Under mild drought condition, elevated CO2 concentration increased net photosynthetic rate of millet leaves at the booting stage by 37.9%, but did not affect water use efficiency at this stage. Elevated CO2 concentration increased net photosynthetic rate and water use efficiency of millet leaves under mild drought condition at the filling stage by 15.0% and 44.2%, respectively. Under mild drought condition, elevated CO2 concentration increased the content of peroxidase (POD) and soluble sugar in millet leaves at the booting stage by 39.3% and 8.0%, respectively, but decreased proline content by 31.5%. It increased the content of POD in millet leaves at the filling stage by 26.5% but decreased the content of MDA and proline by 37.2% and 39.3%, respectively. Under mild drought condition, elevated CO2 concentration significantly increased the number of grain spikes by 44.7% and yield by 52.3% in both years compared with normal water condition. The effect of elevated CO2 concentration on grain yield under mild drought conditions was higher than that under normal water condition. Under mild drought conditions, elevated CO2 concentration increased leaf thickness, vascular bundle sheath cross-sectional area, net photosynthetic rate, and water use efficiency of millet, improved the antioxidant oxidase activity, and changed the concentration of osmotic regulatory substances, alleviated the nega-tive effect of drought on foxtail millet, and finally increased the number of grains per ear and yield of foxtail millet. This study would provide a theoretical basis for millet production and sustainable agricultural development in arid areas under future climate change.

Differential physiological responses and tolerance to potentially toxic elements in Primula forbesii Franch.

Environmental pollution caused by potentially toxic elements (PTEs) has become a global problem that endangers environmental sustainability due to industrial, agricultural, and urban pollution. Primula forbesii Franch. (a synonym of Primula filipes G. Watt.) is a biennial flower native to China with excellent stress resistance and ornamental value. In this study, we examined the phenotypic traits, growth indexes, and physiological properties of P. forbesii in response to five representative PTEs (Cd, Ni, Cr(III), Cu, and Zn) under hydroponic culture conditions. High concentrations of Zn and Cr had little effect on the growth and physiological properties of P. forbesii, indicating that the species has strong tolerance to Zn and Cr stress. Alternatively, high concentrations of Cd, Ni, and Cu seriously affected plant growth and development, resulting in leaf chlorosis and even death, and therefore may have a serious negative impact on the growth of P. forbesii. However, activity levels of some antioxidant enzymes and osmotic regulatory substances remained high, indicating that P. forbesii resisted PTE stress by regulating physiological and biochemical metabolism to a certain extent. Furthermore, principal component analysis and membership function were used to comprehensively evaluate P. forbesii resistance to PTEs. These analyses revealed that P. forbesii exhibits distinct sensitivities and physiological responses to different PTEs and suggested that the resistance to five PTEs in decreasing order is Zn > Cr > Cd > Cu > Ni. These results provide a theoretical basis for the future application of P. forbesii in environments with PTE pollution and may expand its practical utilization.

Growth Response Of Tomato (Solanum lycopersicum) To The Combination Of Aloe Vera And Tauge (Flammulina velutipes) Extract)

Utilization of appropriate plant species, one of which is aloe vera (Aloe vera) and bean sprouts (Flammulina velutipes), which are plant species whose extracts can be utilized as ZPT (Growth Regulatory Substances). The research was conducted in November 2022 with a total of 3 weeks of observations. The purpose of this study was to determine the growth response of tomato (Solanum lycopersicum) to a combination of aloe vera and bean sprouts (Flammulina velutipes) extracts. The materials used included tomato seeds, water, aloe vera extract and bean sprouts while the tools used included polybags, soil testers, hoes, gembor and stationery. The method in this study was carried out by RAK (Random Random Control) using 4 treatments including 0 cc, 15 cc, 20 cc, 25 cc with 3 weeks of observation. Watering is done 3 days once a week. The results obtained showed that treatment 3 (20 cc) had a significant impact on tomato growth.

Smoking cessation, harm reduction, and biomarkers protocols in the PhenX Toolkit: Tools for standardized data collection

The use of standard protocols in studies supports consistent data collection, improves data quality, and facilitates cross-study analyses. Funded by the National Institutes of Health, the PhenX (consensus measures for Phenotypes and eXposures) Toolkit (https://www.phenxtoolkit.org) is a catalog of recommended measurement protocols that address a wide range of research topics and are suitable for inclusion in a variety of study designs. In 2020, a PhenX Working Group of smoking cessation experts followed a well-established consensus process to identify and recommend measurement protocols suitable for inclusion in smoking cessation and smoking harm reduction studies. The broader scientific community was invited to review and provide feedback on the preliminary recommendation of the Working Group. Fourteen selected protocols for measuring smoking cessation, harm reduction, and biomarkers research associated with smoking cessation were released in the PhenX Toolkit (https://www.phenxtoolkit.org/domains/view/330000) in February 2021. These protocols complement existing PhenX Toolkit content related to tobacco regulatory research, substance use and addiction research, and other measures of smoking-related health outcomes. Adopting well-established protocols enables consistent data collection and facilitates comparing and combining data across studies, potentially increasing the scientific impact of individual studies.

Overexpression of the VyP5CR gene increases drought tolerance in transgenic grapevine (V. vinifera L.)

Proline is an important osmotic regulatory substance that can rapidly accumulate in plants under drought stress. A key gene in the proline biosynthesis pathway is P5CR, which responds to abiotic stresses and hormones. When the VyP5CR gene cloned from extremely drought-resistant Chinese wild grape Vitis yeshanensis accession 'Yanshan-1′ is overexpressed in Arabidopsis thaliana, drought tolerance improves. In this study, the effect of VyP5CR on drought resistance was examined in transgenic grapevine, and its upstream regulatory factors were determined. The results showed that when VyP5CR was overexpressed in V. vinifera cultivar 'Thompson Seedless', transgenic vines were more drought-tolerant than the wild type under drought stress, with much less wilting and significantly smaller stomatal apertures and lower transpiration rate. Malondialdehyde content, electrolyte leakage, and H2O2 and O2− accumulations were lower, but the contents of chlorophyll and proline, the net photosynthetic rate and the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) were higher. The expression of drought stress-related genes was also significantly up-regulated in transgenic plants. Thus, VyP5CR increased drought tolerance of transgenic grapevine. Yeast one-hybrid and luciferase activity assays indicated that MADS-box transcription factors VyAGL42 and VyMADS23 directly bound to the VyP5CR gene promoter and activated its transcription. Therefore, VyAGL42 and VyMADS23 might synergistically regulate drought tolerance of grapes with VyP5CR.

Integrated Physiological and Transcriptomic Analyses Revealed Improved Cold Tolerance in Cucumber (Cucumis sativus L.) by Exogenous Chitosan Oligosaccharide

Cucumber (Cucumis sativus L.), sensitive to cold stress, is one of the most economically important vegetables. Here, we systematically investigated the roles of exogenous glycine betaine, chitosan, and chitosan oligosaccharide in alleviating cold stress in cucumber seedlings. The results showed that 50 mg·L-1 chitosan oligosaccharide had the best activity. It effectively increases plant growth, chlorophyll content, photosynthetic capacity, osmotic regulatory substance content, and antioxidant enzyme activities while reducing relative electrical conductivity and malondialdehyde levels in cucumber seedlings under cold stress. To reveal the protective effects of chitosan oligosaccharide in cold stress, cucumber seedlings pretreated with 50 mg·L-1 chitosan oligosaccharide were sampled after 0, 3, 12, and 24 h of cold stress for transcriptome analysis, with distilled water as a control. The numbers of differentially expressed genes in the four comparison groups were 656, 1274, 1122, and 957, respectively. GO functional annotation suggested that these genes were mainly involved in "voltage-gated calcium channel activity", "carbohydrate metabolic process", "jasmonic acid biosynthetic", and "auxin response" biological processes. KEGG enrichment analysis indicated that these genes performed important functions in "phenylpropanoid biosynthesis", "MAPK signaling pathway-plant", "phenylalanine metabolism", and "plant hormone signal transduction." These findings provide a theoretical basis for the use of COS to alleviate the damage caused by cold stress in plant growth and development.

Prohexadione-calcium alleviates the leaf and root damage caused by salt stress in rice (Oryza sativa L.) at the tillering stage.

Salt stress, as a principal abiotic stress, harms the growth and metabolism of rice, thus affecting its yield and quality. The tillering stage is the key growth period that controls rice yield. Prohexadione-calcium (Pro-Ca) can increase the lodging resistance of plants by reducing plant height, but its effects on rice leaves and roots at the tillering stage under salt stress are still unclear. This study aimed to evaluate the ability of foliar spraying of Pro-Ca to regulate growth quality at the rice tillering stage under salt stress. The results showed that salt stress reduced the tillering ability of the rice and the antioxidant enzyme activity in the roots. Salt stress also reduced the net photosynthetic rate (Pn), stomatal conductance (Gs) and intercellular CO2 concentration (Ci) of the rice leaves and increased the contents of osmotic regulatory substances in the leaves and roots. The application of exogenous Pro-Ca onto the leaves increased the tiller number of the rice under salt stress and significantly increased the photosynthetic capacity of the leaves. Additionally, it increased the activities of antioxidant enzymes and the AsA content. The contents of an osmotic regulation substance, malondialdehyde (MDA), and H2O2 in the leaves and roots also decreased. These results suggested that Pro-Ca can increase the tillering ability, photosynthetic capacity, osmotic adjustment substance content levels and antioxidant enzyme activity levels in rice and reduce membrane lipid peroxidation, thus improving the salt tolerance of rice at the tillering stage.