摘要
【目的】研究核桃JrFUL基因的序列特征及在核桃雌雄异熟开花机制中的作用。【方法】以核桃雌先型品种‘极早丰’及雄先型品种‘新早丰’的雌雄花芽为材料,外部形态测量确定不同品种核桃雌雄花芽形态分化差异。通过qRTPCR技术,分析核桃JrFUL、JrAP1、JrLFY及JrSOC1基因在两个核桃品种不同发育时期的雌、雄花芽中的表达模式。克隆核桃JrFUL基因CDS序列,对其结构进行分析。【结果】春季萌芽期后,2月26日雌、雄花芽的横、纵径逐渐开始出现显著差异。不同核桃品种同一时期的雌、雄花芽的几个基因表达量有所差异。克隆得到的核桃JrFUL基因CDS编码区的全长序列长度为747 bp,命名为JrFUL,编码248个氨基酸。NCBI数据库Blast比对表明核桃JrFUL基因与其他植物物种FUL同源基因的相似性较高。系统进化分析发现核桃JrFUL与连香树及葡萄的FUL亲缘关系最近。【结论】JrFUL基因可能在核桃开花进程中起到关键作用,可能对雄花的开放有促进作用。JrLFY与JrSOC1基因可能一定程度上促进核桃开花,JrAP1基因可能一定程度上抑制核桃开花。
【Objective】Walnut is one of the most important dry fruit tree species in China.Walnut is a typical plant with dichogamy,which means the flowering periods of the male and female flowers are inconsistent.This physiological phenomenon leads to a low pollination and fruit-set rates.Therefore,it is of great importance to reveal the flowering mechanism to dichogamy in walnut.The purpose of this study was to determine the roles of some flowering genes,especially for the JrFUL gene.By comparing the morphological and structural similarities and differences between walnut and other plants,we hoped to create a suitable method for studying the flowering mechanism in walnut.【Methods】The male and female flower buds of‘Jizaofeng’with protoganous type and‘Xinzaofeng’with proterandrous type were used as experimental materials.The morphological measurement was applied to determine the differences in external morphology between two cultivars.The transverse and vertical diameters of the female and male flower buds in different periods were measured and analyzed.Three periods based on external morphological differences were selected for next step experiment.Based on the annotation information of walnut genome-wide genes,the sequences of JrFUL,JrAP1,JrLFY and JrSOC1 genes of walnut were obtained.The expression patterns of JrAP1,JrLFY and JrSOC1 in female and male flower buds of two cultivars at different developmental stages were analyzed by Quantitative Real-time PCR.The JrFUL was selected as a candidate gene.The complete CDS(coding sequence)of JrFUL gene was amplified by PCR amplification technique,and its structure and function were analyzed.【Results】The results showed that the Feb 26th was the critical period.Before the period,there was no significant difference in the transverse and vertical diameters of flower buds between two varieties.And after the period,the significant differences came out.The female flower buds of protoganous‘Jizaofeng’were longer in transverse and vertical diameters than the proterandrous‘Xinzaofeng’,while the reverse was true in the male flower buds between two cultivars.Then three periods of Feb 6th,Mar 21st and Apr 7th were selected to carry on the next studies.The expression levels of JrFUL,JrLFY,JrAP1 and JrSOC1 genes of male and female flower buds of two varieties were different in three fixed periods.At the same period,the expression levels of JrFUL,JrLFY,JrAP1 and JrSOC1 genes in female and male flower buds of two varieties were different.The full-length CDS of JrFUL with a length of 747 bp was cloned,encoding 248 amino acids.It had a highly conserved MADS-box domain(2nd-76th)and a semi-conserved Kbox domain(100th-174th).The blast alignment in the NCBI database indicated that JrFUL had a high similarity with other plant species.It was confirmed that it was a FUL homologous gene of walnut,and then we named it as JrFUL.It showed an 81%similarity with FUL(Arabidopsis thaliana),and similarities with FUL genes of other species were more than 60%.Among them,the similarity between JrFUL and CjFUL(Cercidiphyllum japonicum)was 64.4%,the similarity between JrFUL and PsFUL(Parrotia subaequalis)was 65.9%,the similarity between JrFUL and VvFUL(Vitis vinifera)was 63.2%,and the similarity between JrFUL and HmFUL(Hydrangea macrophylla)was 63.2%.Phylogenetic analysis showed that JrFUL had the closest relationships with Cercidiphyllum japonicum and Vitis vinifera,both reaching to a similarity of 82%.【Conclusion】Feb 26th can be a critical period before spring flower bud break of walnut.The transverse and vertical diameters of female and male flower buds of two walnut varieties began to show significant differences after this period.The expression levels of JrFUL,JrLFY,JrAP1 and JrSOC1 genes in female and male flower buds of two walnut varieties at the same period were different.JrFUL gene may play a key role in the flowering process of walnut and may have a more promoting effect on male flowers.To some extent,JrLFY and JrSOC1 genes may promote walnut flowering and JrAP1gene may act as a disincentive to walnut flowering.
作者
王企
陈利娜
夏小丛
敬丹
李好先
骆翔
曹尚银
WANG Qi;CHEN Lina;XIA Xiaocong;JING Dan;LI Haoxian;LUO Xiang;CAO Shangyin(Zhengzhou Fruit Research Institute,Chinese Academy of Agricultural Sciences,Zhengzhou 450009,Henan,China)
出处
《果树学报》
CAS
CSCD
北大核心
2019年第8期992-1004,共13页
Journal of Fruit Science
基金
国家科技基础性工作专项重点项目（2012FY110100）
中国农业科学院科技创新工程（CAAS-ASTIP-2019-ZFRI-03）
