IRREGULAR POLLEN EXINE2 Encodes a GDSL Lipase Essential for Male Fertility in Maize
IRREGULAR POLLEN EXINE2 Encodes a GDSL Lipase Essential for Male Fertility in Maize
复制标题
DOI：
10.1104/pp.20.00105
复制
发表时间：
2020-11-01
期刊：
影响因子：
7.4
通讯作者：
Liu, Juan
中科院分区：
文献类型：
--
作者：
Huo, Yanqing;Pei, Yuanrong;Liu, Juan
花药角质层和花粉外壁是保护植物生殖细胞免受环境胁迫的两个物理屏障；任何一个的缺陷常常导致雄性不育。在这里，我们报道了玉米（Zea mays）的雄性不育突变体不规则花粉外壁2（ipe2）的特征，该突变体表现出花药收缩并且成熟花粉粒中没有淀粉积累。我们克隆了因果基因 IPE2，并通过一系列补充实验证实了其在玉米雄性育性中的作用。 IPE2 在 8 至 9 阶段的玉米发育花药中特异性表达，并编码内质网定位的 GDSL 脂肪酶。 IPE2的功能障碍导致绒毡层和中层的延迟退化，导致花药角质层和花粉外壁的形成缺陷，以及完全雄性不育。 ipe2发育花药中脂肪族代谢发生了很大改变，脂质成分尤其是C16/C18脂肪酸及其衍生物的含量显着降低。我们的研究阐明了 GDSL 在花药和花粉发育中的功能，并为杂交玉米育种提供了有前景的遗传资源。
Anther cuticle and pollen exine are two physical barriers protecting plant reproductive cells against environmental stresses; defects in either often cause male sterility. Here, we report the characterization of a male-sterile mutant irregular pollen exine2 (ipe2) of maize (Zea mays), which displays shrunken anthers and no starch accumulation in mature pollen grains. We cloned the causal gene IPE2 and confirmed its role in male fertility in maize with a set of complementary experiments. IPE2 is specifically expressed in maize developing anthers during stages 8 to 9 and encodes an endoplasmic-reticulum-localized GDSL lipase. Dysfunction of IPE2 resulted in delayed degeneration of tapetum and middle layer, leading to defective formation of anther cuticle and pollen exine, and complete male sterility. Aliphatic metabolism was greatly altered, with the contents of lipid constituents, especially C16/C18 fatty acids and their derivatives, significantly reduced in ipe2 developing anthers. Our study elucidates GDSL function in anther and pollen development and provides a promising genetic resource for breeding hybrid maize.