Enhanced CO2 driven root development coordinates the spatial recruitment
of diazotrophs in rice
Abstract
The comprehension of the reciprocal interaction between root development
and its co-adapted beneficial microbes in response to elevated CO
2 (eCO 2) will facilitate the
identification of nutrient-efficient cultivars for a sustainable
agriculture. Here systemically morphological, anatomical, chemical and
gene expression assays performed under eCO 2 highlight
the divergent root differentiation driven endodermal barrier development
with respect to the L-/S-shaped lateral roots under low nitrogen
conditions in rice. Next, by metabolome and endodermal-cell specific RNA
sequencing we showed that rice adapted to eCO 2 by
spatially recruiting diazotrophs through flavonoid secretion in L-shaped
lateral roots. To the end, using a rice Casparian strip mutant
Oscasp1-1 we validated such root differentiation driven specific
recruitment of a diazotrophic family Oxalobacteraceae implicated
in plant tolerance to low nitrogen availability. Our work indicates that
rice could coordinate nutrient uptake and root differentiation by the
recruitment of diazotrophs in L-shaped lateral roots under climate
change.