文献类型： 外文期刊

作者： Qi, Yingwei ¹ ; Wu, Hanxiao ¹ ; Liu, Jia ¹ ; Chen, Lijuan ¹ ; Jiang, Zitao ¹ ; Zhang, Yujie ³ ; Tian, Xueting ¹ ; Li, Rui ¹ ;

作者机构： 1.Northwest A&F Univ, Coll Hort, Yangling 712100, Shaanxi, Peoples R China

2.Guangdong Acad Agr Sci, Sericultural & Agrifood Res Inst, Key Lab Funct Foods, Minist Agr & Rural Affairs,Guangdong Key Lab Agr, Guangzhou 510610, Peoples R China

3.Forestry Workstn Lintong Dist, Xian 710000, Peoples R China

关键词： Persimmon; Gene expression; Lycopene beta-cyclase; Carotenoid biosynthesis; Gene function

期刊名称：SCIENTIA HORTICULTURAE （ 影响因子：3.463； 五年影响因子：3.672 ）

ISSN： 0304-4238

年卷期： 2021 年 287 卷

页码：

收录情况： SCI

摘要： The aim of the current study was to characterize the functional role of DkLCYb in carotenoid biosynthesis in persimmon fruit. The accumulation of carotenoids and the expression of carotenogenic genes were investigated during persimmon fruit development and postharvest ripening. DkLCYb was cloned and its functional role in carotenoid biosynthesis was characterized. The results showed that carotenoids constantly accumulated during persimmon fruit development and postharvest ripening. More carotenoids accumulated during postharvest storage than during fruit development. The carotenoid composition of unsaponified extracts of the persimmon fruit flesh showed that the major carotenoids were lycopene and beta-carotene in 'Huoguan' and 'Heishi', respectively. Consistent with this result, the expression of six carotenogenic genes increased to their highest levels during postharvest storage. The selected carotenoid biosynthesis genes showed an increased expression pattern during fruit development and in the early period of postharvest storage. A significant decrease in carotenogenic genes was found after stage 6 (DkPSY, DkLCYb, DkZDS and DkBCH) or stage 5 (DkLCYe,). Both DkLCYe and DkBCH showed a steady increase from stage 1 to stage 5; however, dramatically decreased expression of DkLCYe and sharply increased expression of DkBCH were found at stage 6. Correlation analysis showed that the expression of DkPSY, DkPDS, DkZDS, DkLCYb and DkBCH was significantly correlated with the accumulation of one or more carotenoid compounds analysed in this study. However, a negative correlation was found between the expression of DkLCYe and the accumulation of lycopene, beta-cryptoxanthin and zeaxanthin. Specifically, expression of DkLCYb showed the highest correlation (p < 0.01) with beta-carotene (r = 0.74) accumulation. We cloned DkLCYb and analysed its functions in vitro and in vivo. DkLCYb contained typical domains that were highly conserved and essential for lcyb protein activity. The cyclization activity of the encoded protein was demonstrated by functional analysis in E. coli BL21. Transient overexpression of DkLCYb significantly enhanced the accumulation of beta-carotene in persimmon fruit. These results indicate that DkLCYb is a genuine lycopene cyclase gene and it plays an essential role in beta, beta-carotenoid (beta-carotene and beta-cryptoxanthin) biosynthesis in persimmon fruit.