摘要
[目的]本研究旨在探究弱光下荷花花芽败育的成因及相关机制。[方法]以荷花种藕品种‘霞光染指’‘红盏托珠’和‘雪恋’为材料,从生理、分子遗传学角度分析弱光诱导在荷花花芽败育的成因。[结果]与对照(全光照)相比,遮阴处理使植物生长受阻,开花量显著下降,花期延迟并缩短;光合特性分析显示,3个品种光补偿点下降,其中‘雪恋’光补偿点最低;弱光下可溶性糖含量下降,且对蔗糖含量影响最大;Tunnel染色结果显示细胞凋亡是弱光引起花芽败育的主要原因。组学数据揭示引起细胞凋亡的重要基因NnSnRK1在弱光及其他胁迫,如水淹胁迫、铜胁迫、热胁迫等,与NnTPS1呈现出相反的表达模式;RT-qPCR表达量分析表明,遮阴处理下,荷花NnTPS1表达量下降,NnSnRK1表达量上升;外源施加低浓度蔗糖可以提高NnTPS1基因表达量。[结论]荷花在遮阴处理的弱光环境下,发生严重的花芽败育现象,而细胞程序性死亡是弱光引起花芽败育的主要原因;弱光下蔗糖含量降低引起NnTPS1表达量下降,减弱了对NnSnRK1的抑制可能是诱导荷花花芽败育的关键原因。
[Objectives]The purpose of this study was to investigate the cause and related mechanisms of flower abortion under low light intensity. [Methods]The lotus seedlings of‘Xiaguangranzhi’‘Hongzhantuozhu’and‘Xuelian’were used to analyze the causes of low light-induced flower bud abortion from physiological,molecular and genetic perspectives. [Results]Compared with the control(full light),shading treatment suppressed growth and flowering rate of lotus,and delayed flowering. Photosynthetic analysis showed that the light compensation points of the three varieties decreased,and the‘Xuelian’had the lowest light compensation point. The content of soluble sugar decreased under low light,and the content of sucrose was the most affected by shading. Tunnel staining showed that the apoptosis was the main cause of flower bud abortion caused by low light. The transcriptome data revealed that the expression level of NnSnRK1,an important gene in causing apoptosis,increased following decreasing light intensity. Under other stresses,such as flooding stress,copper stress,heat stress,etc.,NnTPS1 also showed the opposite expression pattern.RT-qPCR expression analysis showed that the expression level of NnTPS1 in lotus decreased,while the expression level of NnSnRK1 increased under the shading treatment. Exogenous application of low concentrations of sucrose could increase the expression level of NnTPS1. [Conclusions]In the low light environment of shading treatment,severe flower bud abortion occurred,and programmed cell apoptosis was the main cause of flower bud abortion caused by low light.The decrease of NnTPS1 expression level caused by the decrease of sucrose content under low light reduced the inhibition of NnSnRK1 might be the key reason for inducing lotus flower abortion.
作者
张晓
任惠惠
曹婧
苗其军
金奇江
王彦杰
徐迎春
ZHANG Xiao;REN Huihui;CAO Jing;MIAO Qijun;JIN Qijiang;WANG Yanjie;XU Yingchun(College of Horticulture,Nanjing Agricultural University,Nanjing 210095,China;Zhangji Center Community Agriculture Center,Xiaojian Town,Xiangshui,Jiangsu Province,Xiangshui 224613,China)
出处
《南京农业大学学报》
CAS
CSCD
北大核心
2019年第6期1040-1049,共10页
Journal of Nanjing Agricultural University
基金
国家自然科学基金项目(31772346,31971710)
