State Key Laboratory of Plant Cell and Chromosome Engineering, Innovative Academy of Seed Design, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
University of Chinese Academy of Sciences, 100864 Beijing, China.
Plant Physiol. 2020 Nov;184(3):1438-1454. doi: 10.1104/pp.20.00105. Epub 2020 Sep 10.
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 () of maize (), which displays shrunken anthers and no starch accumulation in mature pollen grains. We cloned the causal gene and confirmed its role in male fertility in maize with a set of complementary experiments. 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 developing anthers. Our study elucidates GDSL function in anther and pollen development and provides a promising genetic resource for breeding hybrid maize.
花粉外壁和花药表皮是保护植物生殖细胞免受环境胁迫的两种物理屏障；这两种结构的缺陷通常会导致雄性不育。在这里，我们报道了玉米雄性不育突变体 ()的特征，该突变体表现为花药皱缩，成熟花粉粒中无淀粉积累。我们克隆了该基因 ，并通过一系列互补实验证实了其在玉米雄性育性中的作用。 基因在玉米发育的花药 8 到 9 期特异性表达，编码一个内质网定位的 GDSL 脂肪酶。IPE2 功能失调导致绒毡层和中层退化延迟，导致花药表皮和花粉外壁形成缺陷，完全雄性不育。脂肪代谢发生了很大的改变，特别是 C16/C18 脂肪酸及其衍生物的含量在 发育的花药中显著降低。我们的研究阐明了 GDSL 在花药和花粉发育中的功能，并为杂交玉米的培育提供了有前途的遗传资源。
