title: The key regulator of submergence tolerance, SUB1A, promotes photosynthetic and metabolic recovery from submergence damage in rice leaves.
abstract: The submergence-tolerance regulator, SUBMERGENCE1A (SUB1A), of rice (Oryza sativa L.) modulates gene regulation, metabolism and elongation growth during submergence. Its benefits continue during desubmergence through protection from reactive oxygen species and dehydration, but there is limited understanding of SUB1A's role in physiological recovery from the stress. Here, we investigated the contribution of SUB1A to desubmergence recovery using the two near-isogenic lines, submergence-sensitive M202 and tolerant M202(Sub1). No visible damage was detected in the two genotypes after 3 d of submergence, but the sublethal stress differentially altered photosynthetic parameters and accumulation of energy reserves. Submergence inhibited photosystem II photochemistry and stimulated breakdown of protein and accumulation of several amino acids in both genotypes at similar levels. Upon desubmergence, however, more rapid return to homeostasis of these factors was observed in M202(Sub1). Submergence considerably restrained non-photochemical quenching (NPQ) in M202, whereas the value was unaltered in M202(Sub1) during the stress. Upon reaeration, submerged plants encounter sudden exposure to higher light. A greater capability for NPQ-mediated photoprotection can benefit the rapid recovery of photosynthetic performance and energy reserve metabolism in M202(Sub1). Our findings illuminate the significant role of SUB1A in active physiological recovery upon desubmergence, a component of enhanced tolerance to submergence.
authors.affiliation: Department of Crop and Soil Environmental Sciences.
authors.forename: Jasper Benedict
authors.initials: JB
authors.lastname: Alpuerto
authors.affiliation: Department of Crop and Soil Environmental Sciences.
authors.forename: Rana Muhammad Fraz
authors.initials: RM
authors.lastname: Hussain
authors.affiliation: Department of Crop and Soil Environmental Sciences.|Translational Plant Sciences Program, Virginia Tech, Blacksburg, VA, 24061, USA.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fukao
mesh_terms: D000222:Adaptation, Physiological / Q000187:drug effects; D000596:Amino Acids / Q000378:metabolism; D064751:Ammonium Compounds / Q000378:metabolism; D002244:Carbon / Q000378:metabolism; D002734:Chlorophyll / Q000378:metabolism; D003681:Dehydration; D005453:Fluorescence; D018506:Gene Expression Regulation, Plant / Q000187:drug effects; D009566:Nitrates / Q000378:metabolism; D009584:Nitrogen / Q000378:metabolism; D012275:Oryza / Q000235:genetics / Q000378:metabolism* / Q000502:physiology*; D018384:Oxidative Stress / Q000187:drug effects; D010100:Oxygen / Q000494:pharmacology; D010788:Photosynthesis / Q000187:drug effects; D018515:Plant Leaves / Q000187:drug effects / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D013312:Stress, Physiological / Q000187:drug effects
chemical_list: D000596:Amino Acids; D064751:Ammonium Compounds; D009566:Nitrates; D010940:Plant Proteins; D002734:Chlorophyll; D002244:Carbon; D009584:Nitrogen; D010100:Oxygen
keywords: Oryza sativa; desubmergence; energy reserves; flooding; reoxygenation