Kadam Suhas, Abril Alejandra, Dhanapal Arun P, Koester Robert P, Vermerris Wilfred, Jose Shibu, Fritschi Felix B
Division of Plant Sciences, University of Missouri, ColumbiaMO, United States.
Graduate Program in Plant Molecular and Cellular Biology, University of Florida, GainesvilleFL, United States.
Front Plant Sci. 2017 May 30;8:862. doi: 10.3389/fpls.2017.00862. eCollection 2017.
Waterlogging is a significant environmental constraint to crop production, and a better understanding of plant responses is critical for the improvement of crop tolerance to waterlogged soils. Aquaporins (AQPs) are a class of channel-forming proteins that play an important role in water transport in plants. This study aimed to examine the regulation of AQP genes under waterlogging stress and to characterize the genetic variability of AQP genes in sorghum (). Transcriptional profiling of AQP genes in response to waterlogging stress in nodal root tips and nodal root basal regions of two tolerant and two sensitive sorghum genotypes at 18 and 96 h after waterlogging stress imposition revealed significant gene-specific pattern with regard to genotype, root tissue sample, and time point. For some tissue sample and time point combinations, , , , , and expression was differentially regulated in tolerant compared to sensitive genotypes. The differential response of these AQP genes suggests that they may play a tissue specific role in mitigating waterlogging stress. Genetic analysis of sorghum revealed that AQP genes were clustered into the same four subfamilies as in maize () and rice () and that residues determining the AQP channel specificity were largely conserved across species. Single nucleotide polymorphism (SNP) data from 50 sorghum accessions were used to build an AQP gene-based phylogeny of the haplotypes. Phylogenetic analysis based on single nucleotide polymorphisms of sorghum AQP genes placed the tolerant and sensitive genotypes used for the expression study in distinct groups. Expression analyses suggested that selected AQPs may play a pivotal role in sorghum tolerance to water logging stress. Further experimentation is needed to verify their role and to leverage phylogenetic analyses and AQP expression data to improve waterlogging tolerance in sorghum.
涝害是作物生产的一个重要环境限制因素，更好地了解植物的反应对于提高作物对涝渍土壤的耐受性至关重要。水通道蛋白（AQP）是一类形成通道的蛋白质，在植物水分运输中起重要作用。本研究旨在研究涝渍胁迫下AQP基因的调控，并鉴定高粱中AQP基因的遗传变异性。在施加涝渍胁迫后18小时和96小时，对两种耐涝和两种敏感高粱基因型的节根根尖和节根基部区域中响应涝渍胁迫的AQP基因进行转录谱分析，结果显示，在基因型、根组织样本和时间点方面存在显著的基因特异性模式。对于某些组织样本和时间点的组合，与敏感基因型相比，耐涝基因型中的、、、、和表达受到差异调节。这些AQP基因的差异反应表明它们可能在减轻涝渍胁迫中发挥组织特异性作用。高粱的遗传分析表明，AQP基因与玉米和水稻一样被聚类到相同的四个亚家族中，并且决定AQP通道特异性的残基在物种间基本保守。利用50份高粱种质的单核苷酸多态性（SNP）数据构建了基于AQP基因的单倍型系统发育树。基于高粱AQP基因单核苷酸多态性的系统发育分析将用于表达研究的耐涝和敏感基因型置于不同的组中。表达分析表明，所选的AQP可能在高粱耐涝胁迫中起关键作用。需要进一步的实验来验证它们的作用，并利用系统发育分析和AQP表达数据来提高高粱的耐涝性。
