Effect of jasmonic acid-methyl ester on the composition of carbohydrates and germination of yellow lupine (Lupinus luteus L.) seeds

Jasmonic Acid-Treated Cotton Plant Leaves Impair Larvae Growth Performance, Activities of Detoxification Enzymes, and Insect Humoral Immunity of Cotton Bollworm

Enhancement of plant defense by exogenous elicitors is a promising tool for integrated pest management strategy. In the present study, cotton plants were treated with different concentrations (0, 0.01, 0.1, and 1.0 mM) of the natural plant defense elicitor, jasmonic acid (JA), and defense-related indicators in the plants were then determined. The cotton bollworm larvae were fed with JA-treated cotton leaves and larvae performances were discussed in terms of larvae relative growth rate (RGR), larval duration, pupal mass, humoral immunity, and activities of a target enzyme, three detoxification enzymes and two metabolic enzymes. Research results showed that JA treatment increased the contents of gossypol and H₂O₂, and decreased that of the total soluble carbohydrates, and 0.1 mM JA was more powerful in the induction of defense-related parameters. As a consequence, cotton bollworm larvae reared on JA-treated cotton leaves showed slower RGR, prolonged larvae duration, and decreased pupal mass. In addition, when larvae were fed with JA-treated cotton leaves, activities of phenoloxidae (an indicator of humoral immunity) and acetylcholinesterase (AchE, a target enzyme), alkaline phosphatases (ALP), acidic phosphatase (ACP), and three detoxification enzymes, carboxylesterase (CarE), glutathione S-transferase (GST), and cytochrome P450 (P450), were all reduced compared to the control. Taken together, the results suggest that JA can be an alternative agent for pest management by delaying insect growth and inhibiting immune defense and detoxification capacity of the cotton bollworm, which may reduce the use of synthetic pesticides.

Effect of Exogenous Application of Methyl Jasmonate on the Lipid and Carbohydrate Content and Composition of Winter Triticale ( Triticosecale Wittm.) Grain and the Severity of Fungal Infections in Triticale Plants and Grain

Kernels of winter triticale ( Triticosecale Wittm. cv. Dinaro) were analyzed. In the autumn of 2015, the effect of methyl jasmonate (MJ) on the germination of triticale kernels and the development of triticale seedlings was analyzed in a laboratory before kernels were sown in experimental plots. Kernels harvested from plots in August 2016 were analyzed to determine their lipid and carbohydrate content and composition and the severity of fungal infections. Triticale grain was harvested at full maturity. The plots were sprayed with MJ at concentrations of 10^-6 to 10^-3 M in the stem elongation stage (200 L/ha) and in the early milk stage (300 L/ha). Other preventive treatments, fungicides, pesticides, or foliar fertilizers were not applied. Lipids of triticale kernels contained 20 fatty acids (FAs) with the highest proportion of linoleic acid. Methyl jasmonate did not exert a significant effect on the FA composition of kernel lipids treated with the plant hormone during the growing season. Statistical analysis did not reveal significant ( p < 0.05) differences in the total content of soluble carbohydrates in control kernels and in the kernels collected from triticale plants treated with MJ. Methyl jasmonate applied at a concentration of 10^-3 M in BBCH stages 54 and 73 reduced the prevalence of stem base, leaf, and spike diseases. However, the severity of grain infections caused by mycotoxin-producing fungi increased in treatments where MJ was applied at a concentration of 10^-5 M relative to the control treatment. The study describes the results noted in naturally infected plants and provides valuable inputs for agricultural practice, but further research is required to validate the presented findings.

The E3 SUMO ligase AtSIZ1 functions in seed germination in Arabidopsis

Seed germination is an important stage in the lifecycle of a plant because it determines subsequent vegetative growth and reproduction. Here, we show that the E3 SUMO ligase AtSIZ1 regulates seed dormancy and germination. The germination rates of the siz1 mutants were less than 50%, even after a short period of ripening. However, their germination rates increased to wild-type levels after cold stratification or long periods of ripening. In addition, exogenous gibberellin (GA) application improved the germination rates of the siz1 mutants to the wild-type level. In transgenic plants, suppression of AtSIZ1 caused rapid post-translational decay of SLEEPY1 (SLY1), a positive regulator of GA signaling, during germination, and inducible AtSIZ1 overexpression led to increased SLY1 levels. In addition, overexpressing wild-type SLY1 in transgenic sly1 mutants increased their germination ratios to wild-type levels, whereas the germination ratio of transgenic sly1 mutants overexpressing mSLY1 was similar to that of sly1. The germination ratios of siz1 mutant seeds in immature developing siliques were much lower than those of the wild-type. Moreover, SLY1 and DELAY OF GERMINATION 1 (DOG1) transcript levels were reduced in the siz1 mutants, whereas the transcript levels of DELLA and ABSCISIC ACID INSENSITIVE 3 (ABI3) were higher than those of the wild-type. Taken together, these results indicate that the reduced germination of the siz1 mutants results from impaired GA signaling due to low SLY1 levels and activity, as well as hyperdormancy due to high levels of expression of dormancy-related genes including DOG1.

Comparative analysis of chemical compositions between non-transgenic soybean seeds and those from plants over-expressing AtJMT, the gene for jasmonic acid carboxyl methyltransferase

Transgenic overexpression of the Arabidopsis gene for jasmonic acid carboxyl methyltransferase (AtJMT) is involved in regulating jasmonate-related plant responses. To examine its role in the compositional profile of soybean (Glycine max), we compared the seeds from field-grown plants that over-express AtJMT with those of the non-transgenic, wild-type (WT) counterpart. Our analysis of chemical compositions included proximates, amino acids, fatty acids, isoflavones, and antinutrients. Overexpression of AtJMT in the seeds resulted in decreased amounts of tryptophan, palmitic acid, linolenic acid, and stachyose, but increased levels of gadoleic acid and genistein. In particular, seeds from the transgenic soybeans contained 120.0-130.5% more genistein and 60.5-82.1% less stachyose than the WT. A separate evaluation of ingredient values showed that all were within the reference ranges reported for commercially available soybeans, thereby demonstrating the substantial equivalence of these transgenic and non-transgenic seeds.

Beyond gibberellins and abscisic acid: how ethylene and jasmonates control seed germination

Appropriate responses of seeds and fruits to environmental factors are key traits that control the establishment of a species in a particular ecosystem. Adaptation of germination to abiotic stresses and changing environmental conditions is decisive for fitness and survival of a species. Two opposing forces provide the basic physiological mechanism for the control of seed germination: the increasing growth potential of the embryo and the restraint weakening of the various covering layers (seed envelopes), including the endosperm which is present to a various extent in the mature seeds of most angiosperms. Gibberellins (GA), abscisic acid (ABA) and ethylene signaling and metabolism mediate environmental cues and in turn influence developmental processes like seed germination. Cross-species work has demonstrated that GA, ABA and ethylene interact during the regulation of endosperm weakening, which is at least partly based on evolutionarily conserved mechanisms. We summarize the recent progress made in unraveling how ethylene promotes germination and acts as an antagonist of ABA. Far less is known about jasmonates in seeds for which we summarize the current knowledge about their role in seeds. While it seems very clear that jasmonates inhibit germination, the results obtained so far are partly contradictory and depend on future research to reach final conclusions on the mode of jasmonate action during seed germination. Understanding the mechanisms underlying the control of seed germination and its hormonal regulation is not only of academic interest, but is also the ultimate basis for further improving crop establishment and yield, and is therefore of common importance.