摘要
干旱胁迫严重限制了甘蓝型油菜种植面积的扩大和产量的提升.耐旱性是由多基因控制的复杂数量性状,将QTL定位与转录组测序相结合,是鉴定甘蓝型油菜耐旱候选基因的有效手段.本研究对甘蓝型油菜干旱敏感品系三六矮和耐旱品系科里纳-2 构建的F2:6 和F2:8 重组自交系群体幼苗进行正常灌溉和干旱胁迫处理,测定地上部鲜重、地上部干重、叶片相对含水量、丙二醛和可溶性糖含量,利用SSR和SNP多态性分子标记构建遗传连锁图谱,鉴定耐旱相关QTL和候选区间,结合耐旱材料No11 和干旱敏感材料No28 的转录组测序,筛选耐旱相关候选基因.研究结果表明:干旱胁迫使甘蓝型油菜幼苗地上部鲜重、地上部干重和叶片相对含水量下降,使叶片丙二醛和可溶性糖含量上升;耐旱相关 QTL和候选区间分布于 A01、A02、A06、A08、A09、A10、C02、C03、C04、C06 和 C09 染色体;对耐旱材料和干旱敏感材料正常灌溉、干旱 24 h、36 h和 48 h进行转录组分析,主要差异表达基因显著富集到光合作用、脂肪酸代谢、氨基酸代谢、植物激素信号转导、核糖体、昼夜节律及角质、木栓素和蜡质的生物合成等相关途径;将QTL与转录组测序相结合,鉴定到 28 个耐旱相关候选基因,主要编码FLC、bHLH105、TGA4、TEM1、ERF003、ACO3、CHLI1、LHCB6 和PORC等,具有转录因子活性、乙烯产生和信号传导、叶绿素生物合成与结合、叶绿素氧化还原酶以及编码核糖体相关蛋白等功能.这些结果可为揭示甘蓝型油菜耐旱机理及分子标记辅助选育耐旱新品种奠定基础.
Abstract
Drought stress severely limits planting promotion and yield increase in Brassica napus L.Drought tolerance is a com-plex quantitative trait controlled by multiple genes.Combining QTL and transcriptome is an effective method for identifying can-didate genes associated with drought tolerance in B.napus.In this study,the seedlings of F2:6 and F2:8 recombinant inbred lines,constructed by Sanliu'ai(drought sensitivity line)and Kelina-2(drought tolerance line),were treated with drought stress and well watering at seedling stage.Shoot fresh weight,shoot dry weight,leaf relative water content,malondialdehyde content,and soluble sugar content were measured.The QTL and candidate intervals were identified based on genetic linkage maps,which were con-structed using SSR and SNP markers with polymorphism.Subsequently,candidate genes associated with drought tolerance were screened by combining transcriptome sequencing of No11(drought tolerance material)and No28(drought sensitivity material).Drought stress decreased shoot fresh weight,shoot dry weight,and leaf relative water content,and increased the contents of malondialdehyde and soluble sugar.QTL and candidate intervals related to drought tolerance were distributed on chromosome A01,A02,A06,A08,A09,A10,C02,C03,C04,C06,and C09.By transcriptome analysis of drought tolerance and sensitivity materials under well water,drought stress for 24,36,and 48 h,the major different expression genes were enriched in the pathways associated with photosynthesis,fatty acid metabolism,amino acid metabolism,plant hormone signal transduction,ribosome,cir-cadian rhythm and biosynthesis of keratin,cork and wax.A total of 28 candidate genes related to drought tolerance were identified by combining QTL and transcriptome.They coded FLC,bHLH105,TGA4,TEM1,ERF003,ACO3,CHLI1,LHCB6,PORC,etc.,which had transcription factor activity,ethylene production and signal transduction,chlorophyll biosynthesis and binding,chloro-phyll oxidoreductase and encoding ribosome proteins.These results could provide a basis for revealing drought tolerance mecha-nism and molecular breeding of drought tolerance variety in B.napus.
基金项目
国家重点研发计划项目(2022YFD1201600)
重庆市技术创新与应用发展专项重点项目(cstc2021jscxcylhX0003)
维普
万方数据