作者：Hong, LW; Su, WY; Zhang, YY; Ye, CT; Shen, YJ; Li, QSQ

影响因子：5.78

刊物名称：SCIENTIFIC REPORTS

出版年份：2018

卷：8

Mangrove plants adapt to coastal tidal mudfats with specially evolved viviparity seed development. However, very little is known about the genetic and molecular mechanisms of mangrove viviparity. Here, we tested a hypothesis that plant hormone abscisic acid (ABA) plays a signifcant role in precocious germination of viviparous Kandelia obovata seeds by exogenous applications. Through transcriptome analysis of ABA treated seeds, it was found that ABA repressed mangrove fruit growth and development, and there were thousands of genes diferentially expressed. As a result, dynamics of the pathways were dramatically altered. In particular, “Plant hormone signal transduction” and “MAPK signaling pathway” were represented signifcantly. Among diferentially expressed genes, some key genes of ABA signal transduction were induced, while ABA biosynthesis genes were repressed. Take ABI1 and ABI2, key negative regulators in ABA signal pathway, as examples, homologous alignment and a phylogenetic tree in various species showed that ABI1 and ABI2 are highly conserved among various species. The functional similarity of these genes was confrmed by transgenic work in Arabidopsis. Taken together, ABA inhibited mangrove viviparity, but mangroves developed a mechanism to prevent accidently increase of ABA in the harsh environment for maintaining viviparous reproductive strategy.

Figure 1. Efects of exogenous ABA on K. obovata fruit growth. (a) Fruit of K. obovata with or without exogenous ABA treatment. (b) Fruit length in (a). Mean ±SD values were determined from three replicates (n>40). Asterisks represents statistical signifcance (Student’s t-test, * and ***P <0 .05 and 0.001, respectively).