不同外源根系挥发物对杉木响应低磷胁迫的影响机理

[Objective]In order to investigate the effects of volatile organic compounds in plant roots on plant response to stress,the regulatory mechanism of different exogenous root volatiles on Chinese fir's response to low phosphorus stress was clarified.[Methods]In this study,the clones of M25 Chinese fir with low phosphorus tolerance were treated with different exogenous volatiles(syringic acid and 1-butene)at different phosphorus concentrations.The total root length,surface area,volume,diameter,SOD,POD and other indicators of treated Chinese fir seedlings were detected.At the same time,chlorophyll and Fv:Fm in the above-ground part of the seedlings were measured.The phosphorus content,phosphorus accumulation and phosphorus utilization efficiency of above-ground and underground parts were analyzed,and the different proteins in different treatments were analyzed by proteomics method.[Results]1)Different exogenous root volatiles had significant effects on the growth and development of Chinese fir roots.The total root length of Chinese fir seedlings significantly decreased under P01 and P0S treatments,P01 significantly promoted the increase of root surface area,P0S significantly increased MAD,1-butene significantly affected MAD under different phosphorus concentrations.The same phenomenon was observed for apase.In the analysis of antioxidant enzymes,it was found that P01 and P0S could significantly regulate the activity of antioxidant enzymes.2)P0S treatment significantly decreased Fv:Fo and Fv:Fm of Chinese fir seedlings.Exogenous 1-butene under P01 and P11 treatments was significantly higher than that under P1S and P0S treatments.P1D treatment significantly promoted the content of chlorophyll A,chlorophyll B and total chlorophyll.3)Compared with P11,P1S significantly promoted the phosphorus content of the whole Chinese fir seedlings;the phosphorus accumulation under P11 treatment was significantly higher than that under P1S treatment,and the phosphorus accumulation under P01 treatment was significantly lower than that under P11 treatment.4)P01vs P11 group differential proteins(22 down-regulated,34 up-regulated)ABC transporter pathway,chitin recognition proteins,chitinase class I and other functional regions.P0Svs P1S differential proteins(112 downregulated and 145 upregulated)were concentrated in phenylpropionic acid biosynthesis and pyruvate metabolism.P0Svs P01 group differential proteins were concentrated in RNA transport,photosynthesis and other pathways to neutralise protein tyrosine kinase,cellulase and other functional regions.[Conclusion]In this study,we found that the exogenous addition of different root volatiles had different regulatory effects on the growth and development of Chinese fir roots.1-Butene plays an important role in alleviating low phosphorus stress of Chinese fir seedlings by regulating root growth and improving stress resistance.While eugenic acid regulates stress resistance of Chinese fir seedlings in response to low phosphorus stress,dantivanic acid has a stronger response to high phosphorus treatment.Therefore,this study provided an in-depth exploration of the growth and development regulation mechanism of Chinese fir by adding different exogenous volatiles under low P treatment,and also provided a theoretical reference for research on the regulation mechanism of root volatiles under nutrient stress.