文章基本信息

标题：Optimizing Rhizobium-legume symbioses by simultaneous measurement of rhizobial competitiveness and N2 fixation in nodules
本地全文：下载
作者：Marcela A. Mendoza-Suárez ; Barney A. Geddes ; Carmen Sánchez-Cañizares 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2020
卷号：117
期号：18
页码：9822-9831
DOI：10.1073/pnas.1921225117
出版社：The National Academy of Sciences of the United States of America
摘要：Legumes tend to be nodulated by competitive rhizobia that do not maximize nitrogen (N 2 ) fixation, resulting in suboptimal yields. Rhizobial nodulation competitiveness and effectiveness at N 2 fixation are independent traits, making their measurement extremely time-consuming with low experimental throughput. To transform the experimental assessment of rhizobial competitiveness and effectiveness, we have used synthetic biology to develop reporter plasmids that allow simultaneous high-throughput measurement of N 2 fixation in individual nodules using green fluorescent protein (GFP) and barcode strain identification (Plasmid ID) through next generation sequencing (NGS). In a proof-of-concept experiment using this technology in an agricultural soil, we simultaneously monitored 84 different Rhizobium leguminosarum strains, identifying a supercompetitive and highly effective rhizobial symbiont for peas. We also observed a remarkable frequency of nodule coinfection by rhizobia, with mixed occupancy identified in ∼20% of nodules, containing up to six different strains. Critically, this process can be adapted to multiple Rhizobium -legume symbioses, soil types, and environmental conditions to permit easy identification of optimal rhizobial inoculants for field testing to maximize agricultural yield.
关键词：nodulation ; legume ; rhizobium ; competition ; nitrogen-fixing