中国农业科学2026，Vol.59Issue(5)：951-966,16.DOI:10.3864/j.issn.0578-1752.2026.05.003
甘蓝型冬油菜越冬期矮生长点形态建成及多激素调控机制
Morphogenesis of the Low-Growth Point and Its Multi-Hormonal Regulatory Mechanism During Overwintering in Winter Rapeseed(Brassica napus L.)
摘要
Abstract
[Objective]This study aims to clarify the mechanism of plant hormones on the morphology of growth point and their response to cold resistance of Brassica napus,to provide a theoretical basis for breeding winter Brassica napus varieties,expanding its planting area,and increasing yield per unit.[Method]Using 9 rapeseed varieties with distinct winter hardiness as experimental materials,a two year(2023-2025)consecutive field identification of overwintering rate was conducted in Qingyang,Gansu Province.Mid-November samplings were used to quantify shoot to root ratio,growth point height and additional phenotypic indicators of overwintering potential.Paraffin sectioning and trypan-blue/nitroblue tetrazolium staining were used to visualize growth cone morphology,cell death,and superoxide accumulation to evaluate the cold tolerance of different cultivars.Growth point of three representative genotypes that span the full range of cold hardiness(NTS309>Tianyou 14>Qinzao 1)were simultaneously analysed by targeted LC-MS/MS targeted phytohormone profiling and RNA-seq.PCA and O2PLS integrative analyses of the metabolome and transcriptome,the physiological and molecular mechanisms underlying the differences in growth point height among these varieties were systematically analyzed.[Result]The results showed the following:Significant differences were observed among cultivars in overwintering rate,root collar diameter,dry weight,root/shoot ratio,and height of the growing point.Strong cold-tolerant varieties,less reactive oxygen species(ROS)and fewer dead cells observed following cold stress,accompanied by a lower proportion of cells damaged by low temperature,the opposite was true for weak cold-tolerant varieties.Statistical analysis revealed that the overwintering rate was extremely significantly and negatively correlated with growth point height(correlation coefficient r=-0.972,P<0.001).Rapeseed varieties with strong cold-tolerance(e.g.,NTS309)which exhibited an overwintering rate exceeding 70%,had a relatively lower growth point height(approximately 3 cm),additionally,the height of the growth cone(observed in paraffin sections)was only 161.5 μm.In contrast,varieties with weak cold-tolerance(e.g.,Qinzao 1)had growth points that protruded above the soil surface(approximately 5 cm),and their growth cone measured approximately 252.9 μm in height.Integrated analysis of hormone metabolomics and transcriptomics data revealed that the height of rapeseed growth point is regulated by a multi-dimensional regulatory network involving the phytohormones IAA,CKs,GA,JA and ABA.In strong cold-tolerant varieties,the levels of free IAA,conjugated IAA,JA-Ile,GA19,and ABA-GE were significantly up-regulated,whereas those of iP9G,mT9G,and BAP9G were significantly down-regulated.Differentially expressed genes(DEGs)between strong and weak cold-tolerant varieties were significantly enriched in pathways including"tryptophan metabolism","zeatin biosynthesis","plant hormone signal transduction",and"α-linolenic acid metabolism".The orthogonal partial least squares(O2PLS)model indicated that metabolites including IAA-Glu,tZR,and JA-Ile exhibited strong covariance with transcriptional modules,these interactions collectively form a hormone-transcription factor-metabolite feedback loop,which exerts three key regulatory effects:inhibiting cell elongation,promoting meristem dormancy and reducing the height of growth cone and growth points.Ultimately,this regulatory loop enhances the defense capacity of rapeseed against low-temperature freezing damage.[Conclusion]This study is the first to confirm that the"dwarf growth point"of rapeseed is a key morphological marker for overwintering survival,and its formation is finely regulated by a multi-hormone network.关键词
甘蓝型冬油菜/植物激素/生长点/生长锥/抗寒性Key words
winter rapeseed(Brassica napus L.)/plant hormone/growth point/growth cone/cold resistance引用本文复制引用
刘海卿,秦雪雪,金姣姣,孙万仓,柴鹏,祁伟亮,杨刚,李婵,骆雪梅,苏芸芸..甘蓝型冬油菜越冬期矮生长点形态建成及多激素调控机制[J].中国农业科学,2026,59(5):951-966,16.基金项目
甘肃省青年科技基金(24JRRM025)、甘肃省农业农村厅种业攻关项目(GYGG-2024-5)、陇东学院青年博士基金(XYBYZK2209)、国家自然科学基金(32360455)、甘肃省高校教师创新基金(甘教技函[2024]9号)、甘肃省自然科学基金(22JR5RM205)、庆阳市青年科技人才项目(2025RK1030) （24JRRM025）
