CRISPR/Cas9 knockout of EPFL10 reduces stomatal density while maintaining photosynthesis and enhancing water conservation in rice

Abstract

SummaryRice production is of paramount importance for global nutrition and potential yields will be detrimentally affected by climate change. Rice stomatal developmental genetics were explored as a mechanism to improve water use efficiency while maintaining yield under climate stress.Gene-editing of STOMAGEN and its paralog, EPFL10, using CRISPR/Cas9 in rice cv. Nipponbare yielded lines with altered stomatal densities that were functionally characterized. CRISPR/Cas9 mediated knockouts of EPFL10 and STOMAGEN yielded lines with c. 80% and 25% of wild-type stomata, respectively.epfl10 lines with small reductions in stomatal densities are able to conserve water to similar extents as stomagen lines with large stomatal density reductions but do not suffer from any concomitant reductions in stomatal conductance, carbon assimilation, or thermoregulation.The duplicate of STOMAGEN, EPFL10, is a weak positive regulator of stomatal development in rice. epfl10 lines maintained wild-type physiological characteristics while conserving more water. Modest reductions in stomatal densities may be a climate-adaptive approach in rice that can safeguard yield.