Transcriptomic Analysis Reveals a Comprehensive Calcium- and Phytohormone-Dominated Signaling Response in Leymus chinensis Self-Incompatibility
Transcriptomic Analysis Reveals a Comprehensive Calcium- and Phytohormone-Dominated Signaling Response in Leymus chinensis Self-Incompatibility
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DOI：
10.3390/ijms20092356
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发表时间：
2019-05-01
影响因子：
5.6
通讯作者：
Liu, Gongshe
中科院分区：
文献类型：
--
作者：
Chen, Shuangyan;Jia, Junting;Liu, Gongshe
羊草（Leymus chinensis（Trin.）Tzvel.）是禾本科重要的经济和生态饲料。自交不亲和性（SI）限制了其自花授粉后结实率低的种子生产。然而，对绵羊草SI的分子机制的调查是缺乏的。因此，花粉萌发和花粉管生长的显微镜观察，以及雌蕊自花授粉和异花授粉后的转录组学分析，进行。结果表明，自花授粉后10 ~ 30 min，花粉管生长迅速受到抑制，异花授粉后，花粉管生长停止，但仍能正常生长。时间进程比较转录组学揭示了不同的自花授粉和异花授粉之间的转录组动态。产生了一系列SI相关信号传导基因和途径，包括与钙（Ca 2+）信号传导、蛋白质磷酸化、植物激素、活性氧（ROS）、一氧化氮（NO）、细胞骨架和程序性细胞死亡（PCD）相关的基因。提出了一个绵羊草SI反应的分子模型。该模型表明，SI可能会触发一个全面的钙和植物激素为主的信号级联和激活PCD，这可能解释了快速抑制自花粉管生长的细胞学分析观察。这些结果为进一步研究羊草SI的分子机制提供了新的思路。
Sheepgrass (Leymus chinensis (Trin.) Tzvel.) is an economically and ecologically important forage in the grass family. Self-incompatibility (SI) limits its seed production due to the low seed-setting rate after self-pollination. However, investigations into the molecular mechanisms of sheepgrass SI are lacking. Therefore, microscopic observation of pollen germination and pollen tube growth, as well as transcriptomic analyses of pistils after self- and cross-pollination, were performed. The results indicated that pollen tube growth was rapidly inhibited from 10 to 30 min after self-pollination and subsequently stopped but preceded normally after cross-pollination. Time course comparative transcriptomics revealed different transcriptome dynamics between self- and cross-pollination. A pool of SI-related signaling genes and pathways was generated, including genes related to calcium (Ca2+) signaling, protein phosphorylation, plant hormone, reactive oxygen species (ROS), nitric oxide (NO), cytoskeleton, and programmed cell death (PCD). A putative SI response molecular model in sheepgrass was presented. The model shows that SI may trigger a comprehensive calcium- and phytohormone-dominated signaling cascade and activate PCD, which may explain the rapid inhibition of self-pollen tube growth as observed by cytological analyses. These results provided new insight into the molecular mechanisms of sheepgrass (grass family) SI.