Koltun Alessandra, Fuhrmann-Aoyagi Martina Bianca, Cardoso Moraes Larissa Alexandra, Lima Nepomuceno Alexandre, Simões Azeredo Gonçalves Leandro, Mertz-Henning Liliane Marcia
Agronomy Department, State University of Maringá (UEM), Brazil.
Biology Department, State University of Londrina (UEL), Brazil.
Gene. 2022 Feb 5;810:146055. doi: 10.1016/j.gene.2021.146055. Epub 2021 Nov 1.
Water stress drastically hinders crop yield, including soybean - one of the world's most relevant feeding crops - threatening the food security of an ever-growing global population. Hemoglobins (GLBs) are involved in water stress tolerance; however, the role they effectively play in soybean remains underexplored. In this study, in silico and in vivo analyses were performed to identify soybean GLBs, capture their transcriptional profile under water stress, and overexpress promising members to assess how soybean cope with waterlogging. Seven GLBs were found, two GLB1 (non-symbiotic) and five GLB2 (symbiotic or leghemoglobins). Three out of the seven GLBs were differentially expressed in soybean RNA-seq libraries of water stress and were evaluated by real-time PCR. Consistently, GmGLB1-1 and GmGLB1-2 were moderately and highly expressed under waterlogging, respectively. Composite plants with roots overexpressing GmGLB1-1 or GmGLB1-2 (mostly) showed higher transcript abundance of stress-defensive genes involved in anaerobic, nitrogen, carbon, and antioxidant metabolism when subjected to waterlogging. In addition, soybean bearing p35S:GmGLB1-2 had lower HO root content, a reactive oxygen species (ROS), under water excess compared with the control condition. Altogether these results suggest that GmGLB1-2 is a strong candidate for soybean genetic engineering to generate waterlogging-tolerant soybean cultivars.
水分胁迫严重阻碍作物产量，包括大豆（全球最重要的饲料作物之一），威胁着不断增长的全球人口的粮食安全。血红蛋白（GLBs）与水分胁迫耐受性有关；然而，它们在大豆中实际发挥的作用仍未得到充分研究。在本研究中，进行了电子分析和体内分析，以鉴定大豆GLBs，捕捉它们在水分胁迫下的转录谱，并过表达有前景的成员，以评估大豆如何应对涝害。共发现7个GLBs，其中2个为GLB1（非共生型），5个为GLB2（共生型或豆血红蛋白）。7个GLBs中有3个在水分胁迫的大豆RNA测序文库中差异表达，并通过实时PCR进行评估。一致的是，GmGLB1-1和GmGLB1-2在涝害条件下分别中度和高度表达。根系过表达GmGLB1-1或GmGLB1-2的复合植株（大部分）在遭受涝害时，参与厌氧、氮、碳和抗氧化代谢的应激防御基因的转录丰度更高。此外，与对照条件相比，携带p35S:GmGLB1-2的大豆在水分过多时的HO根含量（一种活性氧，ROS）较低。这些结果共同表明，GmGLB1-2是大豆基因工程培育耐涝大豆品种的有力候选基因。
