Ihsan Humera, Khan Muhammad Ramzan, Ajmal Wajya, Ali Ghulam Muhammad
National Institute for Genomics and Advanced Biotechnology (NIGAB), National Agricultural Research Centre, Park Road, Islamabad, Pakistan.
Planta. 2015 May;241(5):1173-87. doi: 10.1007/s00425-015-2247-y. Epub 2015 Jan 29.
WsMAGO2 a duplicated protein in Withania through interactions with MPF2-like proteins affects male fertility by producing fewer flowers and aborted non-viable pollens/seeds regulated by anther-specific GAATTTGTGA motif. The MAGO NASHIs are highly conserved genes that encode proteins known to be involved in RNA physiology and many other developmental processes including germ cell differentiation in animals. However, their structural and functional implications in plants as fertility function proteins remained fragmented. MAGO (shorter name of MAGO NASHI) proteins form heterodimers with MPF2-like MADS-box proteins which are recruited in calyx identity and male fertility in Solanaceous plants. Four MAGO genes namely WsMAGO1 and WsMAGO2 and TaMAGO1 and TaMAGO2 were isolated from Withania somnifera and Tubocapsicum anomalum, respectively. These genes have duplicated probably due to whole genome duplication event. Dysfunction of WsMAGO2 through double-stranded RNAi in Withania revealed suppression of RNA transcripts, non-viable pollens, fewer flowers and aborted non-viable seeds in the developing berry suggesting a role of this protein in many traits particularly male fertility. WsMAGO2 flaunted stronger yeast 2-hybrid interactions with MPF2-like proteins WSA206, WSB206 and TAB201 than other MAGO counterparts. The native transcripts of WsMAGO2 culminated in stamens and seed-bearing berries though other MAGO orthologs also exhibited expression albeit at lower level. Coding sequences of the two orthologs are highly conserved, but they differ substantially in their upstream promoter regions. Remarkably, WsMAGO2 promoter is enriched with many anther-specific cis-motifs common in fertility function genes promoters. Among them, disruption of GAATTTGTGA abolished YFP/GUS gene expression in anthers alluding towards its involvement in regulating expression of MAGO in anther. Our findings support a possible recruitment of WsMAGO2 in fertility trait in Withania. These genes have practical application in hybrid production through cytoplasmic male sterility maintenance for enhancement in crops yield.
WsMAGO2是睡茄属中的一种重复蛋白，它通过与类MPF2蛋白相互作用，通过产生较少的花以及由花药特异性GAATTTGTGA基序调控的败育无活力花粉/种子，影响雄性育性。MAGO NASHIs是高度保守的基因，其编码的蛋白质已知参与RNA生理学以及包括动物生殖细胞分化在内的许多其他发育过程。然而，它们作为育性功能蛋白在植物中的结构和功能意义仍不完整。MAGO（MAGO NASHI的简称）蛋白与类MPF2的MADS盒蛋白形成异二聚体，这些蛋白参与茄科植物花萼特性和雄性育性。分别从睡茄和刺天茄中分离出四个MAGO基因，即WsMAGO1和WsMAGO2以及TaMAGO1和TaMAGO2。这些基因可能由于全基因组复制事件而发生了重复。通过双链RNA干扰使睡茄中的WsMAGO2功能失调，结果显示RNA转录本受到抑制、花粉无活力、花减少以及发育中的浆果中出现败育无活力种子，这表明该蛋白在许多性状特别是雄性育性中发挥作用。与其他MAGO对应物相比，WsMAGO2与类MPF2蛋白WSA206、WSB206和TAB201的酵母双杂交相互作用更强。WsMAGO2的天然转录本在雄蕊和结果的浆果中达到峰值，尽管其他MAGO直系同源物也有表达，不过水平较低。这两个直系同源物的编码序列高度保守，但它们的上游启动子区域有很大差异。值得注意的是，WsMAGO2启动子富含许多在育性功能基因启动子中常见的花药特异性顺式基序。其中，GAATTTGTGA的破坏消除了花药中的YFP/GUS基因表达，暗示其参与调节花药中MAGO的表达。我们的研究结果支持WsMAGO2可能参与睡茄的育性性状。这些基因在通过维持细胞质雄性不育来提高作物产量的杂交生产中具有实际应用价值。
