QTL Mapping For Phenotypic Plasticity In Arabidopsis Thaliana Under Light Effects

In the process of occupying a new niche,plants usually change some traits to adapt to the current environment.This change may not involve the variation of DNA sequences,but is affected by maternal genetic effects,that is,the epigenetic effects of environmental effects can be transmitted from parents to offspring,affecting the phenotypic plasticity of offspring and producing intergenerational plasticity.At present,the research on phenotypic plasticity and intergenerational plasticity is limited to trait analysis or epigenetic analysis,and few quantitative trait mapping methods are used to locate gene loci that regulate phenotypic plasticity and intergenerational plasticity.In this study,Arabidopsis thaliana was used as the experimental material,two kinds of light environments were designed,and the recombinant inbred lines with different line numbers were sown continuously for two generations,and the flowering time,pod number and leaf number were measured.Using the difference of actual plant data in different environments,phenotypic plasticity was divided into intra-generation plasticity,intergenerational plasticity and maternal environment plasticity.Interactive QTL mapping was used to analyze the plasticity inheritance of growth traits in Arabidopsis thaliana.The results are as follows:In intra-generation plasticity,the plants under high light condition showed earlier flowering time,fewer leaves and more pods than those under low light condition;in intergenerational plasticity,Arabidopsis thaliana offspring with the same maternal environment had strong adaptability and advantage,showing the phenomenon of earlier flowering time,more leaves and fewer pods.There were 58 significant sites regulating phenotypic plasticity in flowering generation and 23 significant sites affecting phenotypic plasticity affected by maternal environment.There were 71 significant sites for phenotypic plasticity in the generation regulating the number of pods and 31 significant sites for phenotypic plasticity affected by maternal environment.There were 24 significant sites for phenotypic plasticity in the generation regulating the number of leaves,45 significant sites for cross-representative plasticity under high and low light conditions,and 23 significant sites for phenotypic plasticity affected by maternal environment.Functional annotation of these genes showed that candidate genes involved in DNA methylation were found in each group(AT1G19340,AT1G19430,AT1G21100,AT2G19670,AT5G37170,etc.).Candidate genes related to histone modification(AT5G22650,AT5G40830,AT2G27840,AT1G08460,AT1G14030,etc.).The above results show that plant plasticity is regulated by genes,and the environment experienced by the mother may affect the representative plasticity of the offspring,so as to enhance the ability of the offspring to adapt to the same environment and help species to occupy new niches.In this study,a variety of plasticity combinations and two QTL mapping methods were combined to locate the gene loci that control three kinds of phenotypic plasticity,which provides a new idea for analyzing the genetic mechanism of phenotypic plasticity.