In cotton,fiber length is a key determinant of industrial utility and is one of the most important agricultural traits shaped during domestication.However,the genetic determinants and molecular mechanisms under-lying ...In cotton,fiber length is a key determinant of industrial utility and is one of the most important agricultural traits shaped during domestication.However,the genetic determinants and molecular mechanisms under-lying natural variation in fiber length remain poorly characterized.In this study,we identified GhTTL as a critical positive regulator of fiber elongation through genome-wide association study(GWAS).Natural poly-morphisms in the cis-regulatory element of the GhTTL promoter region were found to significantly affect its binding affinity for the transcription factor GhTALE,thereby modulating GhTTL expression across diverse cotton populations.Mechanistic investigations revealed that GhTTL interacts with GhBIN2,a central negative regulator of the brassinosteroid(BR)signaling pathway,and anchors it to the cell membrane.This reduces cytoplasmic GhBIN2 levels,preventing it from associating with GhBES1,a master transcription factor of BR signaling.As a result,GhBES1 localizes to the nucleus,where it promotes fiber cell elongation.These findings elucidate the molecular basis of natural variation in cotton fiber length and provide deeper insights into the regulation of fiber elongation.In addition,this study identifies potential targets for genetic improvement to enhance cotton fiber quality and yield.展开更多
基金supported by the National Natural Science Foundation of China(grants 32441062 and 32360509)the Natural Science Foundation of Xinjiang Uygur Autonomous Region(2024D01A150)+3 种基金the National Key R&D Program of China(2022YFF1001400)the Xinjiang Science and Technology Program(Tianshan Talent Training Program,grant 2022TSYCCX0087)the Key Research and Development Program of Xinjiang(grant 2022B02052)the Xinjiang Science and Technology Major Project of China(grant 2024A02002).
文摘In cotton,fiber length is a key determinant of industrial utility and is one of the most important agricultural traits shaped during domestication.However,the genetic determinants and molecular mechanisms under-lying natural variation in fiber length remain poorly characterized.In this study,we identified GhTTL as a critical positive regulator of fiber elongation through genome-wide association study(GWAS).Natural poly-morphisms in the cis-regulatory element of the GhTTL promoter region were found to significantly affect its binding affinity for the transcription factor GhTALE,thereby modulating GhTTL expression across diverse cotton populations.Mechanistic investigations revealed that GhTTL interacts with GhBIN2,a central negative regulator of the brassinosteroid(BR)signaling pathway,and anchors it to the cell membrane.This reduces cytoplasmic GhBIN2 levels,preventing it from associating with GhBES1,a master transcription factor of BR signaling.As a result,GhBES1 localizes to the nucleus,where it promotes fiber cell elongation.These findings elucidate the molecular basis of natural variation in cotton fiber length and provide deeper insights into the regulation of fiber elongation.In addition,this study identifies potential targets for genetic improvement to enhance cotton fiber quality and yield.
