A dominant-negative actin mutation alters corolla tube width and pollinator visitation in Mimulus lewisii.
A dominant-negative actin mutation alters corolla tube width and pollinator visitation in Mimulus lewisii.
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DOI：
10.1111/nph.14281
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发表时间：
2017-03
期刊：
影响因子：
--
通讯作者：
Yuan YW
中科院分区：
文献类型：
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作者：
Ding B;Mou F;Sun W;Chen S;Peng F;Bradshaw HD Jr;Yuan YW
所有被子植物物种的三分之一产生花瓣融合成花冠筒的花。花冠筒属性的各种精心设计，如长度，宽度和曲率，使植物能够利用许多专门的传粉者群体。这些精心制作往往有显着不同的密切相关的物种，有助于传粉者转移和传粉介导的生殖隔离和物种形成。然而，很少有人知道这些花冠筒属性的遗传和发育控制。在这里，我们报告的表征monkeyflower种Mimulus lewisii的半显性突变体，花冠管宽度大幅减少，但管长度没有变化。与野生型相比，这种形态学改变导致纯合突变体的熊蜂访问率降低约70%。通过大量分离分析和转基因实验，我们证明突变表型是由肌动蛋白基因的显性负突变引起的。这种突变减少了表皮细胞的宽度，但不长度，可能也减少了横向细胞分裂的数量。这些结果表明，一个令人惊讶的潜在作用的“管家”基因在微调发展的生态重要的花卉性状。
A third of all angiosperm species produce flowers with petals fused into a corolla tube. The various elaborations of corolla tube attributes such as length, width, and curvature have enabled plants to exploit many specialized pollinator groups. These elaborations often differ dramatically among closely related species, contributing to pollinator shift and pollinator-mediated reproductive isolation and speciation. However, very little is known about the genetic and developmental control of these corolla tube attributes. Here we report the characterization of a semi-dominant mutant in the monkeyflower species Mimulus lewisii, with a substantial decrease in corolla tube width but no change in tube length. This morphological alteration leads to a ~70% decrease in bumblebee visitation rate for the homozygous mutant compared to the wild-type. Through bulk segregant analysis and transgenic experiment, we show that the mutant phenotype is caused by a dominant-negative mutation in an actin gene. This mutation decreases epidermal cell width but not length, and probably also reduces the number of lateral cell divisions. These results suggest a surprising potential role for a ‘housekeeping’ gene in fine-tuning the development of an ecologically important floral trait.