Functional Characterization of Two Flowering Repressors SHORT VEGETATIVE PHASE and TERMINAL FLOWER 1 in Reblooming Bearded Iris (Iris spp.).
Functional Characterization of Two Flowering Repressors SHORT VEGETATIVE PHASE and TERMINAL FLOWER 1 in Reblooming Bearded Iris (Iris spp.).
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DOI：
10.1016/j.plantsci.2022.111542
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发表时间：
2022-12
期刊：
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通讯作者：
Z. Fan;Yike Gao;Yaohui Gao;Chunjing Guan;Rong Liu;Shiting Wang;Qixiang Zhang
中科院分区：
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作者：
Z. Fan;Yike Gao;Yaohui Gao;Chunjing Guan;Rong Liu;Shiting Wang;Qixiang Zhang
重新开花的须鸢尾（Irisspp.）春、秋均可开花，延长了观赏期。我们先前的转录组分析表明，短营养期（SVP）在有胡子的虹膜再开花中可能起着调节作用。此外，已经发现，在玫瑰（Rosaspp.）中，连续开花表型是由TFL 1突变引起的。和草莓（Fragaria spp.）为了验证这两个基因在蝴蝶花再开花中的功能，分离了两个基因IgSV和IgTFL 1，并对其进行了功能分析。IgSV和IgTFL 1的过表达拟南芥株系均表现为晚花表型，表明它们具有开花抑制因子的功能。IgSV和IgTFL 1的异位表达还引起花、花序和分支结构的表型变化。此外，IgSVP的同源物与花分生组织身份基因APETALA 1之间存在蛋白质-蛋白质相互作用。表达谱分析表明，无论是一次开花还是二次开花，第二次开花期（T5）的二次开花植株中IgSVP的表达量均显著低于第一次开花期（T1），提示IgSVP可能对二次开花有调控作用。而IgTFL 1的表达水平在T5期显著高于T1期。对这两个重要的开花抑制因子IgSV和IgTFL 1的功能研究，为今后鸢尾的分子育种奠定了基础，如利用CRISPR/Cas9系统敲除关键抑制因子，延长髯毛鸢尾的观赏期。
Reblooming bearded iris (Irisspp.) could bloom in both spring and autumn, which has extended the ornamental periods. Our previous transcriptome analysis has indicated the possible regulatory role ofSHORT VEGETATIVE PHASE(SVP) in reblooming of bearded iris. Moreover, it has been revealed that the mutations ofTERMINAL FLOWER 1(TFL1) led to the continuous-flowering phenotypes in rose (Rosaspp.) and strawberry (Fragaria spp.). In order to verify the functions of these two genes on reblooming in bearded iris,IgSVPandIgTFL1were isolated and functionally characterized. All the overexpression Arabidopsis lines ofIgSVPandIgTFL1generated the late-flowering phenotypes, indicating their functions as flowering repressors. The ectopic expression ofIgSVPandIgTFL1also generated phenotypic changes on flowers, inflorescences and branch structures. Moreover, the protein-protein interaction was found between a homologue ofIgSVPand the floral meristem identity geneAPETALA 1. The expression profiling showed thatIgSVPwas expressed significantly lower in the rebloomers in the second floral initiation stage (T5) than those of the first one (T1) in both the once-bloomers and the rebloomers, suggesting the possible regulation ofIgSVPon reblooming. However, the expression level ofIgTFL1in the rebloomers was significantly higher in T5 than that in T1. The functional characterization of the two important flowering repressorsIgSVPandIgTFL1could lay solid foundation for future molecular breeding of iris, for example, knocking out the key repressors by CRISPR/Cas9 system to extend the ornamental periods of bearded iris.