Department of Plant Sciences, School of Life Sciences, University of Hyderabad, Hyderabad, Telangana, 500046, India.
Central Sericultural Research and Training Institute, Central Silk Board, NH-1A, Gallandar, Pampore, Jammu and Kashmir, 192121, India.
Funct Integr Genomics. 2019 Sep;19(5):703-714. doi: 10.1007/s10142-019-00674-3. Epub 2019 Apr 9.
The development of male sterile plants is a prerequisite to developing hybrid varieties to harness the benefits of hybrid vigor in crops and enhancing crop productivity for sustainable agriculture. In plants, cysteine proteases have been known for their multifaceted roles during programmed cell death, and in ubiquitin- and proteasome-mediated proteolysis. Here, we showed that Arachis diogoi cysteine protease (AdCP) expressed under the TA-29 promoter induced complete male sterility in Indian mustard, Brassica juncea. The herbicide resistance gene bar was used for the selection of transgenic plants. Mustard transgenic plants exhibited male sterile phenotype and failed to produce functional pollen grains. Irregularly shaped aborted pollen grains with groove-like structures were observed in male sterile plants during scanning electron microscopy analysis. The T progeny plants obtained from the seed of primary transgenic male sterile plants crossed with the wild-type plants exhibited segregation of the progeny into male sterile and fertile plants with normal seed development. Further, male sterile plants exhibited higher transcript levels of AdCP in anther tissues, which is consistent with its expression under the tapetum-specific promoter. Our results clearly suggest that the targeted expression of AdCP provides a potential tool for developing male sterile lines in crop plants by the malfunction of tapetal cells leading to male sterility as shown earlier in tobacco transgenic plants (Shukla et al. 2014, Funct Integr Genomics 14:307-317).
雄性不育植物的发展是培育杂交品种以利用杂种优势提高作物生产力、实现可持续农业的前提。在植物中，半胱氨酸蛋白酶在细胞程序性死亡以及泛素和蛋白酶体介导的蛋白水解过程中具有多种作用。在这里，我们表明，在 TA-29 启动子下表达的花生半胱氨酸蛋白酶（AdCP）可诱导芥菜，芸苔属雄性完全不育。使用除草剂抗性基因 bar 用于转基因植物的选择。芥菜转基因植物表现出雄性不育表型，无法产生功能性花粉粒。在扫描电子显微镜分析中，观察到雄性不育植物中的畸形花粉粒具有槽状结构。从与野生型植物杂交的初级转基因雄性不育植物的种子获得的 T 代植物表现出杂种的分离，雄性不育和具有正常种子发育的可育植物。此外，雄性不育植物的花药组织中 AdCP 的转录本水平更高，这与其在绒毡层特异性启动子下的表达一致。我们的研究结果清楚地表明，靶向表达 AdCP 为通过绒毡层细胞的功能障碍导致雄性不育，从而在烟草转基因植物中（Shukla 等人，2014 年，功能整合基因组学 14:307-317）开发作物雄性不育系提供了一种潜在的工具。
