Abstract:
Drought is considered to be a major threat to soybean production worldwide and yet
our current understanding of the effects of drought on soybean productively is largely
based on studies on above-ground traits. Although the roots and root nodules are
important sensors of drought, the responses of these crucial organs and their drought
tolerance features remain poorly characterized. The symbiotic interaction between
soybean and rhizobia facilitates atmospheric nitrogen fixation, a process that provides
essential nitrogen to support plant growth and development. Symbiotic nitrogen fixation
is important for sustainable agriculture, as it sustains plant growth on nitrogen-poor soils
and limits fertilizer use for crop nitrogen nutrition. Recent developments have been made
in our understanding of the drought impact on soybean root architecture and nodule
traits, as well as underpinning transcriptome, proteome and also emerging metabolome
information, with a view to improve the selection of more drought-tolerant soybean
cultivars and rhizobia in the future. We conclude that the direct screening of root and
nodule traits in the field as well as identification of genes, proteins and also metabolites
involved in such traits will be essential in order to gain a better understanding of the
regulation of root architecture, bacteroid development and lifespan in relation to drought
tolerance in soybean.
