Action Of Hydrogen Sulfide In Response To Iron Deficiency Adaptability In Glycine Max Seedlings

Hydrogen sulfide（H₂S）as the third gas signalling molecule with nitric oxide（NO）and carbon monoxide（CO）.H₂ S plays an important role in regulating plant adaptation to drought stress,salt stress,ion toxicity and temperature stress.H₂ S can promote the uptake and transport of iron in gramineous plant maize（Zea mays）,however,there were different mechanisms of iron absorption between dicotyledonous plants and monocotyledonous plants.Thus,in this study,we aim to explore whether H₂ S also involves in regulating the assimilation of iron in dicotyledonous soybean（Glycine max）seedlings.In order to verify whether H₂ S could promote the absorption of iron in soybean seedlings,we discussed the effects of H₂ S on iron uptake and transport of soybean seedlings from physiological and biochemical and stoichiometric measures to investigate the specific function of H₂ S in soybean seedling response to iron deficiency.The main results are as follows:（1）Under the iron deficiency,the addition of H₂ S reduced the content of root apoplast Fe in soybean seedling,and affected the pH of rhizosphere solution and ferric reductase activity,these changes promoted the effective utilization of iron in plant tissues,and then increased the chlorophyll content and effectively alleviated the phenomenon of yellowing.Exogenous H₂ S could significantly enhance the photosynthetic rate and electron transport efficiency and the accumulation of organic matter with soybean seedlings,and finally increased the biomass of soybean seedlings.（2）Iron deficiency can seriously affect the growth of soybean seedling and the absorption of nutrient elements,and the application of exogenous H₂ S can alleviate the symptoms of growth retardation caused by iron deficiency.The C,N,P and K contents and the stoichiometric characteristics also have varying degrees of change.These results indicate that H₂ S could alleviate the adaptability of soybean plants to iron deficiency by regulating the stoichiometry of nutrient elements and the absorption of iron.（3）H₂S increased the available Fe content by increasing the utilization of iron in roots.H₂ S could enhance the adaptation of iron deficiency of soybean seedlings by promoting transportation of iron to leaves and regulating stoichiometric characteristics to maintain the normal growth of soybean seedling under iron limitation condition.