黄方 罗聪 余海霞 范志毅 谢小杰 刘源 莫啸 何新华

摘  要：FRIGIDA（FRI）是植物春化途径中影响成花的关键基因之一。本研究克隆了2个芒果FRI基因，分别命名为MiFRI1和MiFRI2。序列生物信息学分析结果显示，MiFRI1和MiFRI2基因的ORF长度分别为1752、1815 bp，编码584、605个氨基酸，蛋白质分子量为64.98、66.86 kDa。进化树分析结果显示，MiFRI1和MiFRI2分别属于FRIGIDA和FRIGIDA-like两个分支。表达模式分析结果显示，MiFRI1和MiFRI2基因在芒果的叶、茎和芽（花）中均表达。MiFRI1在芒果的营养期和成花转变期之间的各个组织中表达水平均较低，而在花芽分化后期的叶片和芽中表达水平显著升高且达到顶峰。MiFRI2的表达高峰在不同组织中出现的时间不同。2个MiFRIs基因在营养芽转向花芽发育的过程中的顶芽中表达水平均下降，但在花芽分化后期的顶芽中表达水平又再次上升，而在叶片中2个基因的表达高峰均出现在花芽分化后期，但MiFRI1的表达水平高于MiFRI2。说明MiFRIs与芒果的花发育有关，但2个基因发挥功能的程度可能存在差异。

关键词：芒果;FRIGIDA;克隆;生物信息学;表达模式

中图分类号：S813.3     文献标识码：A

Abstract： FRIGIDA （FRI） is one of the key genes which influence flower formation in plant in response to vernalization pathway. In this study， two FRI genes named MiFRI1 and MiFRI2 were cloned in mango. Sequence analysis showed that the open reading frame of MiFRI1 and MiFRI2 genes was 1752 bp and 1815 bp in length， encoding 584 and 605 amino acids with molecular weight 64.98 kDa and 66.86 kDa， respectively. Phylogenetic tree analysis showed that MiFRI1 and MiFRI2 belonged to FRIGIDA and FRIGIDA-like family， respectively. Expression analysis showed that MiFRI1 and MiFRI2 expressed in leaves， stems and buds/flowers. The expression level of MiFRI1 was low in all tested tissues between vegetative stage and flowering transition stage， while MiFRI1 increased transcriptional level to the peak in leaves and buds at the later stage of bud differentiation. The expression peak of MiFRI2 varied among different tissues. The expression level of both MiFRIs genes decreased in the terminal bud during the vegetative bud transition to flower bud， but increased again in the bud at the later stage of flower bud differentiation. The peak of MiFRIs both occurred in leaves at the late stage of flower bud differentiation， but the transcriptional level of MiFRI1 was higher than that of MiFRI2. It indicates that MiFRIs may play important roles to the flower development in mango.

Keywords： mango; FRIGIDA; cloning; bioinformatics; expression analysis

DOI： 10.3969/j.issn.1000-2561.2021.01.003

開花是植物由营养生长向生殖生长的转变过程，是植物个体发育和繁殖的关键环节，适时开花对植物的繁殖成功至关重要[1]，故关于开花的课题属于热点研究。与草本植物相比，木本果树通常具有较长的童期，严重制约木本果树新品种的选育，直接影响经济效益。因此，对木本果树成花分子机制开展研究具有重要的意义[2]。

植物成花过程受内部遗传因子和外界环境因素的协同诱导[3]，涉及复杂的基因调控网络途径主要包括：光周期途径、春化途径、赤霉素途径、自主途径、温敏途径和年龄途径[4-5]。……