title: Grain setting defect1, encoding a remorin protein, affects the grain setting in rice through regulating plasmodesmatal conductance.
abstract: Effective grain filling is one of the key determinants of grain setting in rice (Oryza sativa). Grain setting defect1 (GSD1), which encodes a putative remorin protein, was found to affect grain setting in rice. Investigation of the phenotype of a transfer DNA insertion mutant (gsd1-Dominant) with enhanced GSD1 expression revealed abnormalities including a reduced grain setting rate, accumulation of carbohydrates in leaves, and lower soluble sugar content in the phloem exudates. GSD1 was found to be specifically expressed in the plasma membrane and plasmodesmata (PD) of phloem companion cells. Experimental evidence suggests that the phenotype of the gsd1-Dominant mutant is caused by defects in the grain-filling process as a result of the impaired transport of carbohydrates from the photosynthetic site to the phloem. GSD1 functioned in affecting PD conductance by interacting with rice ACTIN1 in association with the PD callose binding protein1. Together, our results suggest that GSD1 may play a role in regulating photoassimilate translocation through the symplastic pathway to impact grain setting in rice.
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Jinshan
authors.initials: J
authors.lastname: Gui
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Chang
authors.initials: C
authors.lastname: Liu
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Junhui
authors.initials: J
authors.lastname: Shen
authors.affiliation: National Key Laboratory of Plant Molecular Genetics, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China lgli@sibs.ac.cn.
authors.forename: Laigeng
authors.initials: L
authors.lastname: Li
mesh_terms: D001692:Biological Transport / Q000235:genetics; D050260:Carbohydrate Metabolism / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D004269:DNA, Bacterial; D018506:Gene Expression Regulation, Plant; D009154:Mutation; D012275:Oryza / Q000235:genetics / Q000502:physiology*; D010539:Permeability; D052585:Phloem / Q000235:genetics / Q000378:metabolism; D010750:Phosphoproteins / Q000235:genetics / Q000378:metabolism*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D030821:Plants, Genetically Modified; D031425:Plasmodesmata / Q000378:metabolism*; D012639:Seeds / Q000235:genetics / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D004269:DNA, Bacterial; D010750:Phosphoproteins; D010940:Plant Proteins; C036483:T-DNA; C103794:remorin