Hydrogen Sulfide As A Signal Molecules Influence The Growth In Arabidopsis Thaliana

Hydrogen sulfide?H₂S?,colourless and smells like rotten eggs.With low molecular weight,H₂ S can pass through cytomembrane discretionarily.The H₂ S gas which was thought toxic at early stages.Through further research H₂ S has become third gaseous signal molecules after nitric oxide and carbon dioxide.Researches have been widely reported that H₂ S regulates plant stress response.The effects of H₂ S on plant growth need to be further studied.This study takes NaHS as exogenous donor,observes the influence to wild-type arabidopsis growth with physiological concentration of H₂ S.It is include the leaf length,width,number and height of plant aerial part;leaf chlorophyll content,net photosynthetic rate,transpiration rate and stomatal conductance,intercellular space CO2 concentration;the related-gene expressions of photosynthes such as Rubicso,RCA,LHCB3,LHCB2 and GPD.The main results show that:1.Blade is the main organ for photosynthesis of green plants,two weeks after Arabidopsis thaliana,the cotyledons were opened and the exogenous H₂ S treatment was started.The growth status of the H₂ S treatment group and the control group was measured every 3 days.The statistics show that:compared with control group,the H₂ S arabidopsis did not change the leaf length,width and numbers.the H₂ S which is processed delay the bolting time of Arabidopsis thaliana,it is also cause plants' height differences during the bolting,but H₂ S have no significant influence for plant height after bolting.2.Photosynthesis is an important medium of carbon-oxygen balance in nature,and it is an important process of manufacturing and supplying nutrients for plants.Net photosynthetic rate,transpiration rate,stomatal conductance and intercellular CO2 concentration were the main parameters of photosynthetic efficiency.Exogenous H₂ S processing starts at 2 weeks after arabidopsis sowing,when cotyledon is open.Determinate four kinds ofphotosynthetic efficiency indicators of arabidopsis that H₂ S processed for the17 th,24th and 31 st day and the control group respectively.Compared with control group,the net photosynthesis rate for arabidopsis which is processed by H₂ S for 24 and 31 days is risen.For arabidopsis processed by H₂ S for 17 and 31 days,both ranspiration rate and stomata conductance are higher than the control group,but the CO2 concentration is lower.Chlorophyll content can be used as a measure of plant energy and an important reference of carbon exchange process.The changes of photosynthetic efficiency and arabidopsis chlorophyll content are closely linked.The chlorophyll content of Arabidopsis which is 24 days H₂ S processed is higher than the control group.3.The regulation of photosynthetic performance is closely related to photosynthesis gene expression quantity.Rubisco?RCA?LHCB3?LHCB2 and GPD play an important role on plant photosynthetic carbon assimilation as optical system structure related proteins.Semi-quantitative RT-PCR results showed that,the expression of Rubisco,RCA,LHCB2,LHCB3 and GPD were correlated with the photosynthesis-related genes of Arabidopsis thaliana by different physiological concentrations of H₂ S.The results showed that: the physiological concentration of exogenous H₂ S increased the net photosynthetic rate,transpiration rate and stomatal conductance to reduce the intercellular CO2 concentration and improve the photosynthetic efficiency by up-regulating the transcription level of photosynthesis-related genes.