Fujian Provincial Key Laboratory of Genetic Engineering for Agriculture, Institute of Biotechnology, Fujian Academy of Agricultural Sciences, Fuzhou 350003, China.
Fujian Provincial Key Laboratory of Genetic Engineering for Agriculture, Institute of Biotechnology, Fujian Academy of Agricultural Sciences, Fuzhou 350003, China.
Sci Total Environ. 2021 Apr 10;764:144508. doi: 10.1016/j.scitotenv.2020.144508. Epub 2020 Dec 16.
Rice cultivation is the primary source of anthropogenic methane (CH), which dramatically impacts global climate change. A growing body of evidence shows that optimizing photosynthate distribution is important for increasing rice yields and mitigating CH emissions. Therefore, the molecular rice breeding with a barley HvSUSIBA2 gene that confers elevated photosynthate flux to grains, is predicted to enhance rice yield and mitigate CH emissions in paddies. Here, in a series of field experiments with differences in growing season and rice variety, we show that SUSIBA2 rice reduced CH emissions from paddies. SUSIBA2 rice grown in the early rice season and late rice season showed similar mitigation effects, with reduction rates of 50.98% for early rice and 50.97% for late rice. The reduction rate of SUSIBA2 rice during the winter rice season was significantly lower (22.26%) than those of other rice seasons. The reduction rates also varied between rice varieties, and SUSIBA2 japonica rice showed a more significant CH mitigation effect than SUSIBA2 indica rice. Further yield-scaled CH emission analyses indicated that the SUSIBA2 effect did not mitigate CH emissions at the expense of yield. Compared with the wild type, SUSIBA2 rice significantly reduced soil organic carbon properties and the abundance of CH-related microbes, and altered methanogenic and methanotrophic communities, indicating that SUSIBA2 rice released less carbon to the soil, which reduced CH production. Furthermore, a comparison of microbial communities between SUSIBA2 japonica and indica rice revealed different responses of methanogenic and methanotrophic communities, which may partly explain their differences in growth performance and CH mitigation effect. Thus, our results show that SUSIBA2 rice substantially reduces CH emissions and that SUSIBA2 can potentially mitigate the CH emissions of japonica and indica rice under distinct cultivation conditions.
水稻种植是人为甲烷（CH）的主要来源，对全球气候变化有重大影响。越来越多的证据表明，优化光合产物分配对提高水稻产量和减少 CH 排放至关重要。因此，利用赋予谷物高光合产物通量的大麦 HvSUSIBA2 基因进行分子水稻育种，预计将提高水稻产量并减少稻田 CH 排放。在这里，我们在一系列不同生长季节和水稻品种的田间试验中表明，SUSIBA2 水稻减少了稻田 CH 的排放。在早稻季和晚稻季种植的 SUSIBA2 水稻表现出相似的减排效果，早稻的减排率为 50.98%，晚稻的减排率为 50.97%。冬季稻季 SUSIBA2 水稻的减排率明显较低（22.26%）。不同水稻品种的减排率也有所不同，SUSIBA2 粳稻比 SUSIBA2 籼稻表现出更显著的 CH 减排效果。进一步的产量规模 CH 排放分析表明，SUSIBA2 效应没有以牺牲产量为代价来减轻 CH 排放。与野生型相比，SUSIBA2 水稻显著降低了土壤有机碳特性和与 CH 相关的微生物丰度，并改变了甲烷生成菌和甲烷营养菌群落，表明 SUSIBA2 水稻向土壤释放的碳更少，从而减少了 CH 的产生。此外，对 SUSIBA2 粳稻和籼稻微生物群落的比较表明，甲烷生成菌和甲烷营养菌群落的响应不同，这可能部分解释了它们在生长性能和 CH 减排效果上的差异。因此，我们的结果表明，SUSIBA2 水稻显著减少了 CH 的排放，并且 SUSIBA2 可以在不同的栽培条件下潜在地减少粳稻和籼稻的 CH 排放。
