Fac. Ciencias, Lab. de Bioquímica Vegetal, Universidad de Chile, Casilla 653, Santiago, Chile.
Instituto de Investigaciones Agropecuarias, La Platina, Santiago, Chile.
Planta. 2021 Jan 12;253(2):31. doi: 10.1007/s00425-020-03561-5.
In deciduous fruit trees in which dormancy is induced by low temperatures, the expression of DORMACY-ASSOCIATED MADS-BOX genes (DAM) is regulated by CBF/DREB1 transcription factors. In Vitis vinifera, in which dormancy is induced by the photoperiod, VvDAM-SVPs gene expression is regulated by FLOWERING LOCUS T (VvFT). Using the sequences of the six peach (Prunus persica) DORMACY-ASSOCIATED MADS-box genes (DAM) as query, eight putative DAM genes belonging to the family of MADS-box transcription factors and related to the Arabidopsis floral regulators SHORT VEGETATIVE PHASE (SVP) and AGAMOUS LIKE 24 (AGL24) were identified in the V. vinifera genome. Among these, five belong to the subfamily SVP-like genes which have been associated with the regulation of flowering and dormancy in annual and perennial plants, respectively. It has been proposed that they play a direct role in the induction and maintenance of endodormancy (ED) through the regulation of the FLOWERING LOCUS T (FT) gene. In the present study, it is demonstrated that in V. vinifera: (1) VvDAM-SVPs genes are not regulated by ABA/low temperature-induced VvCBFs transcription factors as described for other species of deciduous fruit trees. (2) A contrasting expression pattern between VvDAM3-SVP and VvFT was found under different experimental conditions related to the entry and exit of grapevine buds from ED. (3) Overexpression of VvFT in somatic grapevine embryos (SGE) repressed the expression of VvDAM3-SVP and VvDAM4-SVP. Taken together, the results suggest that VvDAM3-SVP could be associated with ED in grapevine buds, and that its expression could be regulated by VvFT.
在休眠是由低温诱导的落叶果树中，DORMANCY-ASSOCIATED MADS-BOX 基因（DAM）的表达受 CBF/DREB1 转录因子调控。在葡萄中，休眠是由光周期诱导的，VvDAM-SVPs 基因的表达受 FLOWERING LOCUS T（VvFT）调控。利用六个桃（Prunus persica）DORMANCY-ASSOCIATED MADS-box 基因（DAM）的序列作为查询，在葡萄基因组中鉴定出 8 个假定的 DAM 基因，它们属于 MADS-box 转录因子家族，与拟南芥花调控因子 SHORT VEGETATIVE PHASE（SVP）和 AGAMOUS LIKE 24（AGL24）有关。其中，有 5 个属于 SVP-like 基因亚家族，它们分别与一年生和多年生植物的开花和休眠调控有关。有人提出，它们通过调节 FLOWERING LOCUS T（FT）基因，直接参与诱导和维持内休眠（ED）。在本研究中，证明在葡萄中：（1）VvDAM-SVPs 基因不受 ABA/低温诱导的 VvCBFs 转录因子的调控，如其他落叶果树所述。（2）在与葡萄芽从 ED 进入和退出相关的不同实验条件下，发现 VvDAM3-SVP 和 VvFT 之间存在相反的表达模式。（3）在体细胞葡萄胚（SGE）中过表达 VvFT 会抑制 VvDAM3-SVP 和 VvDAM4-SVP 的表达。综上所述，结果表明 VvDAM3-SVP 可能与葡萄芽的 ED 有关，其表达可能受 VvFT 调控。
