Maize Genetics and Breeding Unit, Division of Genetics, Indian Agricultural Research Institute, Pusa, New Delhi, India.
PLoS One. 2013 Aug 6;8(8):e70433. doi: 10.1371/journal.pone.0070433. Print 2013.
Waterlogging causes extensive damage to maize crops in tropical and subtropical regions. The identification of tolerance genes and their interactions at the molecular level will be helpful to engineer tolerant genotypes. A whole-genome transcriptome assay revealed the specific role of genes in response to waterlogging stress in susceptible and tolerant genotypes. Genes involved in the synthesis of ethylene and auxin, cell wall metabolism, activation of G-proteins and formation of aerenchyma and adventitious roots, were upregulated in the tolerant genotype. Many transcription factors, particularly ERFs, MYB, HSPs, MAPK, and LOB-domain protein were involved in regulation of these traits. Genes responsible for scavenging of ROS generated under stress were expressed along with those involved in carbohydrate metabolism. The physical locations of 21 genes expressed in the tolerant genotype were found to correspond with the marker intervals of known QTLs responsible for development of adaptive traits. Among the candidate genes, most showed synteny with genes of sorghum and foxtail millet. Co-expression analysis of 528 microarray samples including 16 samples from the present study generated seven functional modules each in the two genotypes, with differing characteristics. In the tolerant genotype, stress genes were co-expressed along with peroxidase and fermentation pathway genes.
水渍会对热带和亚热带地区的玉米作物造成广泛的损害。在分子水平上鉴定耐水渍基因及其相互作用将有助于培育耐水渍的基因型。全基因组转录组分析揭示了基因在敏感和耐水渍基因型中对水渍胁迫的反应中的特定作用。参与乙烯和生长素合成、细胞壁代谢、G 蛋白激活以及通气组织和不定根形成的基因在耐水渍基因型中上调表达。许多转录因子，特别是 ERFs、MYB、HSPs、MAPK 和 LOB 结构域蛋白，参与了这些性状的调控。负责清除胁迫下产生的 ROS 的基因与参与碳水化合物代谢的基因一起表达。在耐水渍基因型中表达的 21 个基因的物理位置与已知负责适应性性状发育的 QTL 标记区间相对应。在候选基因中，大多数与高粱和谷子的基因具有同源性。对包括本研究中 16 个样本在内的 528 个微阵列样本进行的共表达分析，在两种基因型中分别生成了七个功能模块，其特征不同。在耐水渍基因型中，胁迫基因与过氧化物酶和发酵途径基因共同表达。
