Towards crop flooding resilience by 2030

BAJIC, MARKO; DONNELLY WEST; BAILEY-SERRES JULIA; BRADY, SIOBHAN M.; GERMAIN PAULUZZI; NEELIMA SINHA; REYNOSO MAURICIO ALBERTO; KAISA KAJALA; DEAL, ROGER B.

Conferencia; International Socienty of Plant Anaerobiosis 2019; 2019

International Socienty of Plant Anaerobiosis

Too much water is a significant cause of global food insecurity. All major crops, with the exception of rice, produce lower yields if severely waterlogged or fully inundated for longer than a few days. The members of the International Society of Plant Anaerobiosis community are positioned to help alleviate the consequences of flooding on food security by mobilizing natural genetic variation or engineered solutions that provide flooding resilience without dampening yields. The characterization of rice SUB1A, SNORKEL, AG1, SD1, RNC and key genes, loci and traits in teosinte (Zea), Arabidopsis and wetland species exemplify the programmable cellular and developmental plasticity required to respond to various flood scenarios. Submergence, waterlogging, hypoxia and reoxygenation studies have identified key signals (ethylene, O2, NO, ROS, Ca2+, energy charge) that influence metabolism, physiology and growth. Our goal should be to leverage this knowledge to improve flooding resilience in grain, legume, and nutrient rich crops grown in flood-prone environments. A critical challenge is to pyramid flooding with other climate-related traits including drought and salinity resilience, without a loss of productivity under non-stress conditions. The similarity of resilience/escape mechanisms in rice, Rumex species and Arabidopsis suggest the genetic components needed for flooding survival are present across plant species. To address this question we carried out a high-resolution analysis of chromatin and gene activity in response to submergence in four angiosperms, ranging from a dryland adapted wild Solanum to a wetland crop. The data revealed a conserved core of components as well as an evolutionary flexible multi-tiered regulatory architecture. Combining phylogenomics and cis-regulatory motif occurrence in accessible chromatin regions, we identified 68 highly conserved submergence-activated orthologous gene families with signatures of regulation by four transcription factor families. Although submergence-responsive transcriptional activation was more prevalent in rice, indicating a mode of adaptation, the data indicate that appropriate regulation of these building blocks may facilitate engineering of resilience in other species. Funded by the U.S. National Science Foundation grant IOS-1238243.