菊苣肉质根膨大与其生理及基因表达变化初步研究

Taproot Thickening and Its Changes in Physiology and Gene Expression of Chicory

初步探究菊苣肉质根膨大发育进程的农艺性状、生理指标和基因表达变化,以期进一步探讨肉质根发育的生理和分子调控机理。以盆栽根用菊苣‘Hera’和叶用菊苣‘将军’为材料,获取8个不同发育时期的肉质根样品,对糖和内源激素进行定量分析,并对转录因子基因进行qPCR表达量分析。结果表明,根用菊苣根径、根干质量、根冠比和根库活性均大于叶用菊苣。‘Hera’肉质根果糖、葡萄糖和蔗糖含量分别在S2、S3和S4时期最高,且葡萄糖、果糖含量在各时期均高于‘将军’。‘Hera’肉质根生长素IAA、细胞分裂素CTK和赤霉素GA含量均呈现膨大前期高、中期低、后期较高的态势,转录因子基因CiMYB73、CiERF13、CiNAC017、CibZIP53均在S2时期(播种后38 d)呈现高表达。根用菊苣与叶用菊苣农艺性状差异显著,糖和激素可能协同作用于肉质根的膨大发育,播种后38 d可能为菊苣肉质根膨大发育的关键时期。研究结果对后续菊苣肉质根的遗传调控研究、基因工程改良等有一定的参考价值。

Toexplore the agronomic performance,physiological indicators,and gene expression changes during taproot thickening in chicory(Cichorium intybus L.).potted root chicory cultivar‘Hera’and leaf chicory cultivar‘Commander’were used as materials.Taproot samples from 8 developmental stages were collected to quantitatively analyze sugar and endogenous hormones levels,and qPCR expression of transcription factor genes.The results showed that root diameter,root dry mass,root/shoot ratio,and root sink activity of root chicory were higher than those of leaf chicory.The highest levels of fructose,glucose,and sucrose in‘Hera’'s taproot occurred during the S2,S3,and S4 periods,respectively,with the glucose and fructose contents higher in taproot of‘Hera’compared to‘Commander’.Indole-3-acetic acid(IAA),cytokinin(CTK),and gibberellic acid(GA)levels in taproot of‘Hera'was high in the early stage,low in the middle stage and high in the late stage of taproot thickening.Transcription factors CiMYB73,CiERF13,CiNAC017,and CibZIP53 exhibited high expression at 38 days after sowing(S2 stage).It concluded that there is a significant difference in the agronomic traits between potted root chicory and leaf chicory.Sugar and hormones may synergistically affect the taproot thickening,and 38 days after sowing may be a critical period for the development of taproot in chicory.This study provides a reference for future genetic regulation research and genetic engineering improvement of chicory taproots.