Genome-wide analysis of changes in miRNA and target gene expression reveals key roles in heterosis for chinese cabbage biomass  

作　　者：Peirong Li Tongbing Su Deshuang Zhang Weihong Wang Xiaoyun Xin Yangjun Yu Xiuyun Zhao Shuancang Yu Fenglan Zhang 

机构地区：[1]Beijing Vegetable Research Center(BVRC),Beijing Academy of Agriculture and Forestry Sciences(BAAFS),Beijing 100097,China [2]Key Laboratory of Biology and Genetic Improvement of Horticultural Crops(North China),Ministry of Agriculture,Beijing 100097,China [3]Beijing Key Laboratory of Vegetable Germplasm Improvement,Beijing 100097,China

出　　处：《Horticulture Research》2021年第1期731-745,共15页园艺研究（英文）

基　　金：the National Key Research and Development Program of China(2016YFD0101701);the ScientistTraining Program of BAAFS(JKZX201906);the Scie nee and Tech no logy Inno vatio n Capacity Pr oject(KJCX20170710);the Collaborative Innovation Center of BAAFS(KJCX201907-2);the National Natural Science Foundation of China(No.31801852);the Key Program of Beijing Municipal Science and Technology Committee(Z191100004019010);the earmarked fund for the China Agriculture Research System(CARS-23-A-05).

摘　　要：Heterosis is a complex phenomenon in which hybrids show better phenotypic characteristics than their parents do.Chinese cabbage(Brassica rapa L.spp.pekinensis)is a popular leafy crop species,hybrids of which are widely used in commercial production;however,the molecular basis of heterosis for biomass of Chinese cabbage is poorly understood.We characterized heterosis in a Chinese cabbage hybrid cultivar and its parental lines from the seedling stage to the heading stage;marked heterosis of leaf weight and biomass yield were observed.Small RNA sequencing revealed 63 and 50 differentially expressed microRNAs(DEMs)at the seedling and early-heading stages,respectively.The expression levels ofthe majority of miRNA clusters in the hybrid were lower than the mid-parent values(MPVs).Using degradome sequencing,we identi fied 1,819 miRNA target genes.Gene ontology(GO)analyses demonstrated that the target genes ofthe MPV-DEMs and low parental expression level dominance(ELD)miRNAs were signi ficantly enriched in leaf morphogenesis,leaf development,and leaf shaping.Transcriptome analysis revealed that the expression levels of photosynthesis and chlorophyll synthesis-related MPV-DEGs(differentially expressed genes)were signi ficantly different in the F_(1) hybrid compared to the parental lines,resulting in increased photosynthesis capacity and chlorophyll content in the former.Furthermore,expression of genes known to regulate leaf development was also observed at the seedling stage.Arabidopsis plants overexpressing BrGRF4.2 and bra-miR396 presented increased and decreased leaf sizes,respectively.These results provide new insight into the regulation of target genes and miRNA expression patterns in leaf size and heterosis for biomass of B.rapa.

关 键 词：HEADING SEEDLING analysis 

分 类 号：S634.1[农业科学—蔬菜学]