title: Assimilate translocation and expression of sucrose transporter, OsSUT1, contribute to high-performance ripening under heat stress in the heat-tolerant rice cultivar Genkitsukushi.
abstract: High temperature reduces the grain quality of rice, a situation likely to become more frequent because of global warming. We studied the effects of high-temperature stress on grain quality of heat-tolerant cultivar 'Genkitsukushi' and heat-sensitive cultivar 'Tsukushiroman'. When day/night temperatures were 31/26 °C from heading until maturity, the grain quality of 'Genkitsukushi' was rated at the first inspection grade (high quality), whereas 'Tsukushiroman' showed a remarkable increase in the percentage of white immature kernels (low quality). Nonstructural carbohydrate content in the stem of 'Genkitsukushi' the early maturation was significantly higher than in 'Tsukushiroman' and greatly decreased under high temperature. From 14 to 21 days after heading, the expression of the sucrose transporter gene, OsSUT1, was higher in the stem of 'Genkitsukushi' grown under high temperature than in 'Tsukushiroman'. In addition, the expression of OsSUT1 in the grains of 'Genkitsukushi' was significantly higher than in 'Tsukushiroman' during the ripening period. These results indicate that sugar transport functions more effectively in 'Genkitsukushi' than in 'Tsukushiroman', and that the effectiveness of sugar transport contributes to maintaining high grain quality in 'Genkitsukushi' under high-temperature conditions.
authors.affiliation: Fukuoka Agricultural Research Center, Chikushino, Fukuoka 818-8549, Japan; Crop Science Laboratory, Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Miyazaki
authors.forename: Masato
authors.initials: M
authors.lastname: Araki
authors.forename: Kenta
authors.initials: K
authors.lastname: Okamura
authors.forename: Yushi
authors.initials: Y
authors.lastname: Ishibashi
authors.forename: Takashi
authors.initials: T
authors.lastname: Yuasa
authors.forename: Mari
authors.initials: M
authors.lastname: Iwaya-Inoue
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics; D018533:Biomass; D050260:Carbohydrate Metabolism / Q000235:genetics; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D006358:Hot Temperature; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D012275:Oryza / Q000235:genetics* / Q000254:growth & development / Q000502:physiology*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018547:Plant Stems / Q000378:metabolism; D021381:Protein Transport; D012639:Seeds / Q000254:growth & development / Q000502:physiology; D013312:Stress, Physiological / Q000235:genetics
chemical_list: D026901:Membrane Transport Proteins; D010940:Plant Proteins; C078729:sucrose transport protein, plant
keywords: DAH; Grain quality; Grain yield; High temperature; NSC; Nonstructural carbohydrates; OsSUT1; Sucrose transporter; days after heading; nonstructural carbohydrates; rice sucrose transporter 1