Alternate expression of CONSTANS-LIKE 4 in short days and CONSTANS in long days facilitates day-neutral response in Rosa chinensis
Alternate expression of CONSTANS-LIKE 4 in short days and CONSTANS in long days facilitates day-neutral response in Rosa chinensis
复制标题
CONSTANS-LIKE 4在短日照和长日照中的交替表达促进月季的日中性反应
DOI：
10.1093/jxb/eraa161
复制
发表时间：
2020-07-06
影响因子：
6.9
通讯作者：
Wang, Changquan
中科院分区：
文献类型：
--
作者：
Lu, Jun;Sun, Jingjing;Wang, Changquan
光周期开花反应分为三种主要类型：长日（LD）、短日（SD）和中性日（DN）。LD和SD植物对日长的逆反应已在拟南芥和水稻中得到部分表征;然而，DN反应背后的分子机制在很大程度上尚不清楚。现代玫瑰是重要的观赏植物，具有连续开花的特性，通常被认为是DN植物。在此，RcCO和RcCOL 4被鉴定为分别在LD和SD条件下在CF栽培品种月季'Old-Blush'中上调的成花激活因子。通过病毒诱导的基因沉默（VIGS）降低RcCO或/和RcCOL 4的表达，在SD和LD下均延迟开花时间。有趣的是，与RcCO沉默的植物相反，RcCOL 4沉默的植物的开花时间在SD下比在LD条件下更延迟，表明受干扰的植物对白天中性的响应。进一步的分析表明，RcCOL 4和RcCO之间的物理相互作用促进了RcCO与RoFT启动子中的CORE基序的结合和RIFT的诱导。两者合计，在LD中的RcCO和在SD中的RcCOL 4的互补表达保证开花在有利的生长条件下，无论光周期。这一发现建立了玫瑰中CF的分子基础，并进一步阐明了DN反应的潜在机制。
Photoperiodic flowering responses are classified into three major types: long day (LD), short day (SD), and day neutral (DN). The inverse responses to daylength of LD and SD plants have been partly characterized in Arabidopsis and rice; however, the molecular mechanism underlying the DN response is largely unknown. Modern roses are economically important ornamental plants with continuous flowering (CF) features, and are generally regarded as DN plants. Here, RcCO and RcCOL4 were identified as floral activators up-regulated under LD and SD conditions, respectively, in the CF cultivar Rosa chinensis 'Old-Blush'. Diminishing the expression of RcCO or/and RcCOL4 by virus-induced gene silencing (VIGS) delayed flowering time under both SDs and LDs. Interestingly, in contrast to RcCO-silenced plants, the flowering time of RcCOL4-silenced plants was more delayed under SD than under LD conditions, indicating perturbed plant responses to day neutrality. Further analyses revealed that physical interaction between RcCOL4 and RcCO facilitated binding of RcCO to the CORE motif in the promoter of RoFT and induction of RIFT. Taken together, the complementary expression of RcCO in LDs and of RcCOL4 in SDs guaranteed flowering under favorable growth conditions regardless of the photoperiod. This finding established the molecular foundation of CF in roses and further shed light on the underlying mechanisms of DN responses.