title: Expression of three sHSP genes involved in heat pretreatment-induced chilling tolerance in banana fruit.
abstract: BACKGROUND
  Banana fruit is highly susceptible to chilling injury. In previous research it was shown that heat pretreatment of banana fruit at 38 °C for 3 days before storage at a chilling temperature of 8 °C for 12 days prevented increases in visible chilling injury index, electrolyte leakage and malondialdehyde content and also decreases in lightness and chroma, indicating that heat pretreatment could effectively alleviate chilling injury of banana fruit. However, little is known about the role of small heat shock proteins (sHSPs) in postharvest chilling tolerance of banana fruit. In the present study, three cytosolic sHSP expression profiles in peel and pulp tissues of banana fruit during heat pretreatment and subsequent chilled storage (8 °C) were investigated in relation to heat pretreatment-induced chilling tolerance.
  
  
  RESULTS
  Three full-length cDNAs of cytosolic sHSP genes, including two class I sHSP (CI sHSP) and one class II sHSP (CII sHSP) cDNAs, named Ma-CI sHSP1, Ma-CI sHSP2 and Ma-CII sHSP3 respectively, were isolated and characterised from harvested banana fruit. Accumulation of Ma-CI sHSP1 mRNA transcripts in peel and pulp tissues and Ma-CII sHSP3 mRNA transcripts in peel tissue increased during heat pretreatment. Expression of all three Ma-sHSP genes in peel and pulp tissues was induced during subsequent chilled storage. Furthermore, Ma-CI sHSP1 and Ma-CII sHSP3 mRNA transcripts in pulp tissue and Ma-CI sHSP2 mRNA transcripts in peel and pulp tissues were obviously enhanced by heat pretreatment at days 6 and 9 of subsequent chilled storage.
  
  
  CONCLUSIONS
  These results suggested that heat pretreatment enhanced the expression of Ma-sHSPs, which might be involved in heat pretreatment-induced chilling tolerance of banana fruit.
authors.affiliation: College of Life Science, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China.
authors.forename: Li-hong
authors.initials: LH
authors.lastname: He
authors.forename: Jian-ye
authors.initials: JY
authors.lastname: Chen
authors.forename: Jian-fei
authors.initials: JF
authors.lastname: Kuang
authors.forename: Wang-jin
authors.initials: WJ
authors.lastname: Lu
mesh_terms: D000222:Adaptation, Physiological / Q000235:genetics*; D000595:Amino Acid Sequence; D003080:Cold Temperature; D018076:DNA, Complementary; D061353:Food Storage / Q000379:methods; D005638:Fruit / Q000235:genetics* / Q000378:metabolism; D020869:Gene Expression Profiling; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D050888:Heat-Shock Proteins, Small / Q000235:genetics* / Q000378:metabolism; D006358:Hot Temperature; D008969:Molecular Sequence Data; D028521:Musa / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D013696:Temperature
chemical_list: D018076:DNA, Complementary; D050888:Heat-Shock Proteins, Small; D010940:Plant Proteins; D012333:RNA, Messenger