摘要
花青素是植物体内广泛存在的一类天然色素,具有重要的生理功能。花青素合成途径可受多种因素调控,其中植物生长激素赤霉素(gibberellic acid,GA)对其的调控作用报道较少。本文用不同浓度的赤霉素处理心里美萝卜幼苗,以探讨它对花青素含量的影响。结果表明,外源GA_3处理显著增加了萝卜幼苗的下胚轴长度,并提高了下胚轴中α-淀粉酶活性;显著降低下胚轴中花青素的含量。1μmol/L GA_3处理效果较好;处理后第3 d和第5 d,花青素合成的关键酶查尔酮合酶、查尔酮异构酶和花青素还原酶编码基因的表达水平均低于对照组。同时,外源GA_3显著诱导过氧化物酶活性的升高。上述结果表明,外源赤霉素可能通过下调花青素合成基因的表达,提高过氧化物酶活性和促进下胚轴伸长生长降低花青素的水平。
Anthocyanidins are natural pigments in plants with many important functions. The factors to regulate anthocyanidin biosynthetic pathway are largely unknown,including gibberellic acid（ GA） as an important plant growth hormone. The objective of this study was to investigate the effect of exogenous GA_3 on anthocyanidin accumulation in red radish seedlings. The results showed that the hypocotyl length was increased compared with controls. In hypocotyls, the α-amylase activity was upregulated. The anthocyanidin content was reduced. The most pronounced results were found in 1 μmol/L GA_3 treatment.Reduction of anthocyanidin content was in accordance with down-regulated expression of anthocyanidin biosynthesis genes encoding for chalcone synthase,chalcone isomerase and anthocyanidin reductase at the third and fifth day after GA_3 treatments,together with the induction of peroxidase activity. Our findings suggested that exogenous GA_3 was able to reduce anthocyanidin accumulation by down-regulating the expression of related biosynthesis genes and also involving enhanced peroxidase activity during the elongation of hypocotyl.
出处
《中国生物化学与分子生物学报》
CAS
CSCD
北大核心
2016年第3期326-331,共6页
Chinese Journal of Biochemistry and Molecular Biology
基金
河南省教育厅科学技术研究重点项目(No.12A180017)
河南省生物学重点学科
河南师范大学青年科学基金资助项目~~
