Chen Ling-Yun, Zhao Shu-Ying, Wang Qing-Feng, Moody Michael L
Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, Hubei, PR China.
Department of Biological Sciences, University of Texas at El Paso, 500 West University Ave, El Paso, TX, 79968, USA.
Sci Rep. 2015 May 20;5:10098. doi: 10.1038/srep10098.
Adaptation to aquatic habitats is a formidable challenge for terrestrial angiosperms that has long intrigued scientists. As part of a suite of work to explore the molecular mechanism of adaptation to aquatic habitats, we here sequenced the transcriptome of the submerged aquatic plant Ranunculus bungei, and two terrestrial relatives R. cantoniensis and R. brotherusii, followed by comparative evolutionary analyses to determine candidate genes for adaption to aquatic habitats. We obtained 126,037, 140,218 and 114,753 contigs for R. bungei, R. cantoniensis and R. brotherusii respectively. Bidirectional Best Hit method and OrthoMCL method identified 11,362 and 8,174 1:1:1 orthologous genes (one ortholog is represented in each of the three species) respectively. Non-synonymous/synonymous (dN/dS) analyses were performed with a maximum likelihood method and an approximate method for the three species-pairs. In total, 14 genes of R. bungei potentially involved in the adaptive transition from terrestrial to aquatic habitats were identified. Some of the homologs to these genes in model plants are involved in vacuole protein formation, regulating 'water transport process' and 'microtubule cytoskeleton organization'. Our study opens the door to understand the molecular mechanism of plant adaptation from terrestrial to aquatic habitats.
对于陆生被子植物而言，适应水生栖息地是一项艰巨的挑战，长期以来一直吸引着科学家们。作为探索适应水生栖息地分子机制的一系列工作的一部分，我们对沉水水生植物小毛茛及其两个陆生近缘种广州毛茛和藓状毛茛的转录组进行了测序，随后进行了比较进化分析，以确定适应水生栖息地的候选基因。我们分别获得了小毛茛、广州毛茛和藓状毛茛的126,037、140,218和114,753个重叠群。双向最佳比对法和OrthoMCL法分别鉴定出11,362个和8,174个1:1:1直系同源基因（三个物种中各有一个直系同源基因）。对这三个物种对采用最大似然法和近似法进行非同义/同义（dN/dS）分析。总共鉴定出14个可能参与小毛茛从陆生向水生栖息地适应性转变的基因。这些基因在模式植物中的一些同源基因参与液泡蛋白形成、调节“水分运输过程”和“微管细胞骨架组织”。我们的研究为理解植物从陆生到水生栖息地的适应分子机制打开了大门。
