title: Metabolic and transcriptomic signatures of rice floral organs reveal sugar starvation as a factor in reproductive failure under heat and drought stress.
abstract: Heat and drought stress are projected to become major challenges to sustain rice (Oryza sativa L.) yields with global climate change. Both stresses lead to yield losses when they coincide with flowering. A significant knowledge gap exists in the mechanistic understanding of the responses of rice floral organs that determine reproductive success under stress. Our work connects the metabolomic and transcriptomic changes in anthers, pistils before pollination and pollinated pistils in a heat-tolerant (N22) and a heat-sensitive (Moroberekan) cultivar. Systematic analysis of the floral organs revealed contrasts in metabolic profiles across anthers and pistils. Constitutive metabolic markers were identified that can define reproductive success in rice under stress. Six out of nine candidate metabolites identified by intersection analysis of stressed anthers were differentially accumulated in N22 compared with Moroberekan under non-stress conditions. Sugar metabolism was identified to be the crucial metabolic and transcriptional component that differentiated floral organ tolerance or susceptibility to stress. While susceptible Moroberekan specifically showed high expression of the Carbon Starved Anthers (CSA) gene under combined heat and drought, tolerant N22 responded with high expression of genes encoding a sugar transporter (MST8) and a cell wall invertase (INV4) as markers of high sink strength.
authors.affiliation: Max-Planck-Institute of Molecular Plant Physiology, D-14476, Potsdam, Germany.
authors.forename: Xia
authors.initials: X
authors.lastname: Li
authors.affiliation: International Rice Research Institute, DAPO BOX. 7777, Manila, The Philippines.
authors.forename: Lovely M F
authors.initials: LM
authors.lastname: Lawas
authors.affiliation: International Rice Research Institute, DAPO BOX. 7777, Manila, The Philippines.
authors.forename: Richard
authors.initials: R
authors.lastname: Malo
authors.affiliation: Max-Planck-Institute of Molecular Plant Physiology, D-14476, Potsdam, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Glaubitz
authors.affiliation: Max-Planck-Institute of Molecular Plant Physiology, D-14476, Potsdam, Germany.
authors.forename: Alexander
authors.initials: A
authors.lastname: Erban
authors.affiliation: International Rice Research Institute, DAPO BOX. 7777, Manila, The Philippines.
authors.forename: Ramil
authors.initials: R
authors.lastname: Mauleon
authors.affiliation: International Rice Research Institute, DAPO BOX. 7777, Manila, The Philippines.
authors.forename: Sigrid
authors.initials: S
authors.lastname: Heuer
authors.affiliation: Max-Planck-Institute of Molecular Plant Physiology, D-14476, Potsdam, Germany.
authors.forename: Ellen
authors.initials: E
authors.lastname: Zuther
authors.affiliation: Max-Planck-Institute of Molecular Plant Physiology, D-14476, Potsdam, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Kopka
authors.affiliation: Max-Planck-Institute of Molecular Plant Physiology, D-14476, Potsdam, Germany.
authors.forename: Dirk K
authors.initials: DK
authors.lastname: Hincha
authors.affiliation: International Rice Research Institute, DAPO BOX. 7777, Manila, The Philippines.
authors.forename: Krishna S V
authors.initials: KS
authors.lastname: Jagadish
mesh_terms: D000222:Adaptation, Physiological; D050260:Carbohydrate Metabolism; D002241:Carbohydrates; D055864:Droughts; D035264:Flowers / Q000235:genetics / Q000502:physiology*; D018506:Gene Expression Regulation, Plant; D006358:Hot Temperature; D055442:Metabolome; D012275:Oryza / Q000235:genetics / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D054817:Pollination; D013312:Stress, Physiological; D059467:Transcriptome
chemical_list: D002241:Carbohydrates; D010940:Plant Proteins
keywords: anther; metabolite profiling; pistils; pollinated pistils; transcriptional regulation