PavDAM1启动子缺失突变介导的甜樱桃休眠分子机制研究

甜樱桃短低温品种需冷量低开花早，是实现错季和早熟栽培的重要基础。通过日光温室实现了甜樱桃可提前至3月底上市，但春节期间上市则困难重重，缺乏短低温品种是瓶颈。开发与需冷量相关的分子标记有助于加速短低温品种选育。低温对甜樱桃休眠的建立和解除的有着重要影响，受低温诱导表达的DAM基因在休眠中起着核心调控作用。申请人前期研究发现，低需冷量（300h）品种“罗亚理”比高需冷量（1000h）品种“红灯”打破休眠早。在休眠期间“罗亚理”PavDAM1基因表达量显著低于“红灯”。深入研究发现，“罗亚理”PavDAM1启动子相较于“红灯”有大片段（655bp）缺失突变，与低需冷量密切相关。基于该突破性发现，拟开展甜樱桃PavDAM1启动子缺失序列的作用元件预测和酵母单杂筛库，筛选出上游的低温响应因子，探究其表达趋势和功能，解析低温调控休眠分子机理，为开发需冷量分子标记和短低温品种育种提供创新性的理论基础。

The low chilling requirement and early flowering are important basics for realizing off­season and early maturity cultivation. The sweet cherries are on sale at the end of March via solar greenhouse, but it is difficult for us to sell cherries during Spring Festival. The development of molecular markers related to chilling requirements is the basis for accelerating the selection of low chilling requirement varieties. Low temperature has an important effect on the dormancy establishment and release of sweet cherry, and DAM gene plays a core role in dormancy regulation. Our previous studies showed that the transcript level of PavDAM1 was lower in the low-chill cultivar ‘Royal Lee’ (300h) than that of high-chill cultivar ‘Hongdeng’ (1000h). There was a fragment deletion (655bp) in PavDAM1 promoter of ‘Royal Lee’ compared with ‘Hongdeng’. Based on previous studies, deletion fragment will be investigated by screening of cis-elements and yeast one-hybrid (Y1H) system to search the factors in response to low temperature. The expression patterns of those factors will be detected by RT-qPCR. We will focus on the molecular mechanism of deletion mutation of PavDAM1 promoter regulating dormancy in response to low temperature in sweet cherries，which will help to molecular-assisted breeding and molecular markers related to chilling requirements.