State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China; Key Laboratory of Plant Nutrition and Fertilization in Lower-Middle Reaches of the Yangtze River, Ministry of Agriculture, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
State Key Laboratory of Crop Genetics and Germplasm Enhancement, College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, 210095, China.
J Environ Manage. 2021 Feb 1;279:111583. doi: 10.1016/j.jenvman.2020.111583. Epub 2020 Nov 10.
Greenhouse gasses (GHG) emission from the agricultural lands is a serious threat to the environment. Plants such as rice (Oryza sativa L.) that are cultivated in submerged conditions (paddy field) contribute up to 19% of CH emission from agricultural lands. Such plants have evolved lysigenous aerenchyma in their root system which facilitates the exchange of O and GHG between aerial parts of plant and rhizosphere. Currently, the regulation of GHG and O via aerenchyma formation is poorly understood in plants, especially in rice. Here, a reverse genetic approach was employed to reduce the aerenchyma formation by analyzing two mutants i.e., oslsd1.1-m12 and oslsd1.1-m51 generated by Tos17 and T-DNA insertion. The wild-type (WT) and the mutants were grown in paddy (flooded), non-paddy and hydroponic system to assess phenotypic traits including O diffusion, GHG emission and aerenchyma formation. The mutants exhibited significant reductions in several morphophysiological traits including 20-60% aerenchyma formation at various distances from the root apex, 25% root development, 50% diffusion of O and 27-36% emission of methane (CH) as compared to WT. The differential effects of the oslsd1.1 mutants in aerenchyma-mediated CH mitigation were also evident in the diversity of (pmoA, mcrA) methanotrophs in the rhizosphere. Our results indicate the novel pathway in which reduced aerenchyma in rice is responsible for the mitigation of CH, diffusion of O and the root growth in rice. Limited aerenchyma mediated approach to mitigate GHG specially CH mitigation in agriculture is helpful technique for sustainable development.
农业土地的温室气体（GHG）排放对环境构成严重威胁。在淹水条件（稻田）下种植的水稻（Oryza sativa L.）等植物对农业土地 CH 排放的贡献率高达 19%。这些植物在其根系中进化出了共质体通气组织，这有利于植物地上部分和根际之间的 O 和 GHG 交换。目前，植物中特别是水稻中，通过通气组织形成来调节 GHG 和 O 的机制还知之甚少。在这里，我们采用反向遗传学方法，通过分析 Tos17 和 T-DNA 插入产生的两个突变体 oslsd1.1-m12 和 oslsd1.1-m51 来减少通气组织的形成。将野生型（WT）和突变体种植在稻田（淹没）、非稻田和水培系统中，以评估包括 O 扩散、GHG 排放和通气组织形成在内的表型特征。与 WT 相比，突变体在几个形态生理特征上表现出显著降低，包括距根尖不同距离的通气组织形成减少 20-60%、根系发育减少 25%、O 扩散减少 50%、甲烷（CH）排放减少 27-36%。oslsd1.1 突变体在通气组织介导的 CH 缓解中的差异效应也在根际中（pmoA、mcrA）甲烷营养菌的多样性中表现出来。我们的结果表明，在水稻中，减少通气组织的新型途径负责 CH 的缓解、O 的扩散和根的生长。在农业中，限制通气组织介导的方法来缓解 GHG，特别是 CH 的缓解，是可持续发展的有用技术。
