Gain and Loss of Floral Scent Production through Changes in Structural Genes during Pollinator-Mediated Speciation
Gain and Loss of Floral Scent Production through Changes in Structural Genes during Pollinator-Mediated Speciation
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DOI：
10.1016/j.cub.2016.10.023
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发表时间：
2016-12-19
期刊：
影响因子：
9.2
通讯作者：
Kuhlemeier, Cris
中科院分区：
文献类型：
--
作者：
Amrad, Avichai;Moser, Michel;Kuhlemeier, Cris
植物与传粉者的相互作用被认为是被子植物进化的驱动力。对新传粉者的适应涉及由多个基因控制的多个花性状的协调变化。令人惊讶的是，这种复杂的遗传变化在进化过程中发生了无数次。在这里，我们报告的遗传基础上的变化，在这样一个性状，花香排放，在属矮牵牛（茄科）。在从蜜蜂到天蛾授粉的转变过程中挥发物的数量和复杂性的增加是由于编码苯甲酸/水杨酸羧基甲基转移酶（BSMT）和苯甲酰辅酶A：苯甲醇/ 2-苯基乙醇苯甲酰转移酶（BPBT）的基因的从头表达，以及苯丙烷/苯途径的大多数酶的转录水平适度增加。肉桂酸CoA连接酶（CNL）功能的丧失以及MYB转录因子ODO 1表达的减少解释了从蛾到蜂鸟授粉过渡期间气味的丧失。在蜂鸟适应物种的CNL基因是无活性的，由于终止密码子，但似乎也经历了随着时间的推移进一步降解。因此，我们建议，气味的损失发生在相对较早的过渡到蜂鸟授粉，并可能之前的紫外线吸收黄酮醇的损失。发现CNL也参与了在从异交到自交的过渡过程中的气味的丧失在Capsella（菊科）（见随附的论文）提出了有趣的问题，关于进化变化的目标的深层进化保护的可能原因。
The interactions of plants with their pollinators are thought to be a driving force in the evolution of angiosperms. Adaptation to a new pollinator involves coordinated changes in multiple floral traits controlled by multiple genes. Surprisingly, such complex genetic shifts have happened numerous times during evolution. Here we report on the genetic basis of the changes in one such trait, floral scent emission, in the genus Petunia (Solanaceae). The increase in the quantity and complexity of the volatiles during the shift from bee to hawkmoth pollination was due to de novo expression of the genes encoding benzoic acid/salicylic acid carboxyl methyltransferase (BSMT) and benzoyl-CoA: benzylalcohol/ 2-phenylethanol benzoyltransferase (BPBT) together with moderately increased transcript levels for most enzymes of the phenylpropanoid/benzenoid pathway. Loss of cinnamate-CoA ligase (CNL) function as well as a reduction in the expression of the MYB transcription factor ODO1 explain the loss of scent during the transition from moth to hummingbird pollination. The CNL gene in the hummingbird-adapted species is inactive due to a stop codon, but also appears to have undergone further degradation over time. Therefore, we propose that loss of scent happened relatively early in the transition toward hummingbird pollination, and probably preceded the loss of UV-absorbing flavonols. The discovery that CNL is also involved in the loss of scent during the transition from out-crossing to selfing in Capsella (Brassicaceae) (see the accompanying paper) raises interesting questions about the possible causes of deep evolutionary conservation of the targets of evolutionary change.