Yang Liwen, Fu Jianxin, Qi Shuai, Hong Yan, Huang He, Dai Silan
Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment and College of Landscape Architecture, Beijing Forestry University, Beijing 100083, PR China.
Beijing Key Laboratory of Ornamental Plants Germplasm Innovation & Molecular Breeding, National Engineering Research Center for Floriculture, Beijing Laboratory of Urban and Rural Ecological Environment and College of Landscape Architecture, Beijing Forestry University, Beijing 100083, PR China.
Gene. 2017 Jun 20;617:32-43. doi: 10.1016/j.gene.2017.02.020. Epub 2017 Feb 16.
Cryptochrome (CRY), a vital photoreceptor which mediates light signals, controls photomorphogenesis in higher plants. However, the function of CRY in mediating light to regulate growth and development of ornamental plants is still unclear. In this study, we identified two CRY1 homologous genes, ClCRY1a and ClCRY1b, from Chrysanthemum lavandulifolium, a diploid wild chrysanthemum species. Expression analysis demonstrated that these two ClCRY1 genes showed the highest expression levels in seedlings leaves that were transferred to short day (SD) conditions for eight days. ClCRY1a was expressed at a higher level in the dark phase of SD, while ClCRY1b was expressed more highly in SD than that in long day (LD) conditions. Overexpression of either ClCRY1a or ClCRY1b in wild-type (WT) Arabidopsis resulted in early flowering under both LD and SD. The expression levels of GIGANTEA (GI) and FLOWERING LOCUS T (FT) were significantly up-regulated in ClCRY1a overexpressors under both LD and SD. Moreover, the transcript levels of GI, CONSTANS (CO) and FT were markedly increased in ClCRY1b overexpressors under LD; nevertheless, only the expression levels of CO and FT were up-regulated under SD. Taken together, the above results indicated that these two ClCRY1 genes could regulate flowering time via different pathways in C. lavandulifolium under LD and SD conditions. Our results provided evidence for the role of ClCRY1s in controlling photomorphogenesis and laid a foundation for further study on the molecular mechanism of ClCRYs mediating light signals to control floral transition.
隐花色素（CRY）是一种重要的光感受器，可介导光信号，控制高等植物的光形态建成。然而，CRY在介导光调节观赏植物生长发育中的功能仍不清楚。在本研究中，我们从二倍体野生菊花物种香叶菊中鉴定出两个CRY1同源基因，ClCRY1a和ClCRY1b。表达分析表明，这两个ClCRY1基因在转移到短日（SD）条件下8天的幼苗叶片中表达水平最高。ClCRY1a在SD的黑暗阶段表达水平较高，而ClCRY1b在SD中的表达水平高于长日（LD）条件下。在野生型（WT）拟南芥中过表达ClCRY1a或ClCRY1b都会导致在LD和SD条件下提前开花。在LD和SD条件下，ClCRY1a过表达植株中GIGANTEA（GI）和开花位点T（FT）的表达水平均显著上调。此外，在LD条件下，ClCRY1b过表达植株中GI、CONSTANS（CO）和FT的转录水平显著增加；然而，在SD条件下，只有CO和FT的表达水平上调。综上所述，上述结果表明，在LD和SD条件下，这两个ClCRY1基因可通过不同途径调节香叶菊的开花时间。我们的结果为ClCRY1s在控制光形态建成中的作用提供了证据，并为进一步研究ClCRYs介导光信号控制花期转换的分子机制奠定了基础。
