Histological and single-nucleus transcriptome analyses reveal the specialized functions of ligular sclerenchyma cells and key regulators of leaf angle in maize  

作　　者：Qibin Wang Qiuyue Guo Qingbiao Shi Hengjia Yang Meiling Liu Yani Niu Shuxuan Quan Di Xu Xiaofeng Chen Laiyi Li Wenchang Xu Fanying Kong Haisen Zhang Pinghua Li Bosheng Li Gang Li 

机构地区：[1]State Key Laboratory of Wheat Improvement,College of Life Sciences,Shandong Agricultural University,Tai’an 271018,China [2]Peking University Institute of Advanced Agricultural Sciences,Shandong Laboratory of Advanced Agriculture Sciences in Weifang,Weifang,Shandong 261325,China [3]State Key Laboratory of Wheat Improvement,College of Agronomy,Shandong Agricultural University,Tai’an 271018,China

出　　处：《Molecular Plant》2024年第6期920-934,共15页分子植物（英文版）

基　　金：supported by the National Natural Science Foundation of China(32270263);the Key R&D Program of Shandong Province(ZR202211070163);the Taishan Scholars program(to B.L.),and the China Postdoctoral Science Foundation(2023M742154).

摘　　要：Leaf angle(LA)is a crucial factor that affects planting density and yield in maize.However,the regulatory mechanisms underlying LA formation remain largely unknown.In this study,we performed a comparative histological analysis of the ligular region across various maize inbred lines and revealed that LA is significantly influenced by a two-step regulatory process involving initial cell elongation followed by subsequent lignification in the ligular adaxial sclerenchyma cells(SCs).Subsequently,we performed both bulk and single-nucleus RNA sequencing,generated a comprehensive transcriptomic atlas of the ligular region,and identified numerous genes enriched in the hypodermal cells that may influence their specialization into SCs.Furthermore,we functionally characterized two genes encoding atypical basic-helix-loop-helix(bHLH)transcription factors,bHLH30 and its homolog bHLH155,which are highly expressed in the elongated adaxial cells.Genetic analyses revealed that bHLH30 and bHLH155 positively regulate LA expansion,and molecular experiments demonstrated their ability to activate the transcription of genes involved in cell elongation and lignification of SCs.These findings highlight the specialized functions of ligular adaxial SCs in LA regulation by restricting further extension of ligular cells and enhancing mechanical strength.The transcriptomic atlas of the ligular region at single-nucleus resolution not only deepens our understanding of LA regulation but also enables identification of numerous potential targets for optimizing plant architecture in modern maize breeding.

关 键 词：PLANTING specialized angle 

分 类 号：S513[农业科学—作物学]