Mechanism Of Stomatal Action Of β-aminobutyric Acid On Soybean And Its Water-saving Effect

Each stoma is formed of two specialised guard cells and they play crucial roles in the uptake of carbon dioxide(CO2)for photosynthesis,as well as driving the transportation of mineral nutrients associated with water transpiration.The guard cells,which are able to open and close the stomatal pore through changes in cell turgor.Stomatal aperture is regulated by many environmental stimuli such as light,atmospheric CO2 concentration,atmospheric relative humidity and abscisic acid(ABA)Since stomata make a significant contribution to the control of WUE,stomatal research is crucial for tackling future water scarcity.However,although researchers have done a lot of in-depth research on the signal transduction mechanism of stomatal response to environmental factors or abscisic acid,few research results have been applied to crop productionβ-aminobutyric acid,BABA,is a broad-spectrum resistance inducer and there is evidence that root irrigation of BAB A promotes plant resistance to disease,drought and salt stress,however,its regulation on stomatal movement and its water-saving effect have been neglected for a long time.In this project,we conducted greenhouse and field experiments and found that1.BABA cannot trigger stomatal closure per se,and The ABA level in guard cells is not enhanced upon leaf surface spraying of BABA(100 μM),while stomatal sensitivity to ABA is increased by the same treatment2.Leaf surface spraying of BABA(100 μM)alleviate the adverse effects of osmotic stress on photosynthetic apparatus and the antioxidation system in leaves3.The yield and WUE of soybean plants grown in the field under water-deficit conditions are significantly increased by leaf surface spraying of BABA(100 μM)Moreover,these effects show strong correlation with the developmental stages of soybean plantsIn conclusion,the results of this project suggest that BABA is a promising anti-transpirant,which primes stomatal response to ABA and the tolerance of plant photosynthetic and antioxidative systems to osmotic stress.Additionally,BABA is a low-cost chemical that can be widely applied in the arid area to increase crop yields and WUE with good performance.