Beijing Key Laboratory of Growth and Developmental Regulation for Protected Vegetable Crops, College of Horticulture, China Agricultural University, Beijing 100193, China.
Department of Plant Biology, College of Biological Sciences, University of California, Davis, California 95616.
Plant Physiol. 2019 Jun;180(2):986-997. doi: 10.1104/pp.19.00317. Epub 2019 Apr 9.
In plants, male sterility is an important agronomic trait, especially in hybrid crop production. Many factors are known to affect crop male sterility, but it remains unclear whether Suc transporters (SUTs) participate directly in this process. Here, we identified and functionally characterized the cucumber () CsSUT1, a typical plasma membrane-localized energy-dependent high-affinity Suc-H symporter. is expressed in male flowers and encodes a protein that is localized primarily in the tapetum, pollen, and companion cells of the phloem of sepals, petals, filaments, and pedicel. The male flowers of -RNA interference (RNAi) lines exhibited a decrease in Suc, hexose, and starch content, relative to those of the wild type, during the later stages of male flower development, a finding that was highly associated with male sterility. Transcriptomic analysis revealed that numerous genes associated with sugar metabolism, transport, and signaling, as well as with auxin signaling, were down-regulated, whereas most () transcription factor genes were up-regulated in these -RNAi lines relative to wild type. Our findings demonstrate that male sterility can be induced by RNAi-mediated down-regulation of expression, through the resultant perturbation in carbohydrate delivery and subsequent alteration in sugar and hormone signaling and up-regulation of specific transcription factors. This knowledge provides a new approach for bioengineering male sterility in crop plants.
在植物中，雄性不育是一个重要的农艺性状，特别是在杂交作物生产中。许多因素已知会影响作物雄性不育，但尚不清楚蔗糖转运蛋白（SUTs）是否直接参与这一过程。在这里，我们鉴定并功能表征了黄瓜（）CsSUT1，这是一种典型的质膜定位的能量依赖的高亲和力蔗糖-H 共转运蛋白。在雄性花中表达，并编码一种主要定位于绒毡层、花粉和韧皮部伴胞的蛋白质，存在于花萼、花瓣、花丝和花梗的韧皮部中。与野生型相比，-RNAi（RNAi）系的雄性花在雄性花发育后期的 Suc、己糖和淀粉含量下降，这与雄性不育高度相关。转录组分析表明，与糖代谢、运输和信号转导以及生长素信号转导相关的许多基因下调，而这些 -RNAi 系中大多数（）转录因子基因相对于野生型上调。我们的研究结果表明，通过 RNAi 介导的表达下调导致碳水化合物传递受到干扰，从而导致糖和激素信号的改变以及特定（）转录因子的上调，可以诱导雄性不育。这一知识为作物雄性不育的生物工程提供了一种新方法。
