Carotenoid Accumulation and Carotenogenic Genes Expression During Two Types of Persimmon Fruit (Diospyros kaki L.) Development
Carotenoid Accumulation and Carotenogenic Genes Expression During Two Types of Persimmon Fruit (Diospyros kaki L.) Development
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DOI：
10.1007/s11105-010-0272-3
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发表时间：
2011-09
影响因子：
2.1
通讯作者：
Daqiu Zhao;Chunhua Zhou;J. Tao
中科院分区：
文献类型：
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作者：
Daqiu Zhao;Chunhua Zhou;J. Tao
柿（Diospyros kakiL.），属于Ebenaceae科，不仅被用作新鲜水果，而且还用于许多药用用途。类胡萝卜素是柿果实中的主要色素，其组成和含量对柿果的色泽和营养品质有重要影响。本研究对两种类型柿果实的品质指标、类胡萝卜素含量及类胡萝卜素基因表达进行了分析。结果表明，果实颜色与主要成分和类胡萝卜素总量呈正相关。柿果实中类胡萝卜素的积累是由多个类胡萝卜素基因互作的结果，但两种类型柿果实中类胡萝卜素积累的分子机制存在一定差异。作为一个完整的单位，“牛心石”中八氢番茄红素合成酶基因（DkPSY）的表达水平相对较低，导致果实发育早期类胡萝卜素含量较低甚至低于检测限;而“西村川濑”中类胡萝卜素含量较低则是由于除DkPSY以外的其他类胡萝卜素基因的表达水平相对较低。在果实发育后期，DkPSY、八氢番茄红素去饱和酶基因和β-胡萝卜素羟化酶基因（DkBCH）表达水平的提高诱导了类胡萝卜素含量的增加，因为所有的类胡萝卜素基因在“西村酶”中均强烈表达，积累了大量的类胡萝卜素。此外，β-隐黄质是主要成分，其含量随果实成熟度的变化而增加，这主要是由于DkBCH使β-胡萝卜素更多地转化为β-隐黄质。
Persimmon (Diospyros kakiL.), belonging to the Ebenaceae family, has been used not only as a fresh fruit, but also for many medicinal uses. Carotenoids are the main pigment in persimmon fruit, which contribute significantly to fruit color and nutritional quality due to their composition and content. In this study, fruit quality indices, carotenoid contents and expression of carotenogenic genes were analyzed in two types of persimmon fruit. The results demonstrated that there was a positive correlation between fruit color and the contents of main composition and total carotenoids. Carotenoid accumulation in persimmon fruit resulted from the interaction of carotenogenic genes, but the molecular mechanisms responsible for accumulation of carotenoids in two types of persimmon fruit had a few differences. As a complete unit, the relatively low expression level of phytoene synthase gene (DkPSY) in “Niuxinshi” resulted in low carotenoid contents or even under the detection limit at the early fruit developmental stages; but low carotenoid contents in “Nishimurawase” were due to the relatively low expression level of carotenogenic genes other thanDkPSY. At the late fruit developmental stages, increased expression levels ofDkPSY, phytoene desaturase gene and beta-carotene hydroxylase gene (DkBCH) induced elevated carotenoid contents; because all carotenogenic genes strongly expressed in “Nishimurawase”, a large amount of carotenoids were accumulated. In addition, β-cryptoxanthin was the main composition whose content increased with the fruit maturity changes, which was mainly because ofDkBCHwhich might lead more conversion of β-carotene to β-cryptoxanthin.