Sanchez-Ballesta María Teresa, Lluch Yolanda, Gosalbes María José, Zacarias Lorenzo, Granell Antonio, Lafuente María Teresa
Instituto de Agroquímica y Tecnología de Alimentos, Consejo Superior de Investigaciones Científicas, Apartado de Correos 73, 46100 Burjassot, Valencia, Spain.
Planta. 2003 Nov;218(1):65-70. doi: 10.1007/s00425-003-1086-4. Epub 2003 Sep 10.
Long-term storage at low, non-freezing, temperature (1.5 degrees C) induces chilling injury in fruit of Fortune mandarin (Citrus clementina Hort. Ex Tanaka x Citrus reticulata, Blanco), manifested as pitting and brown depressed areas that may end up with local cell death. Pre-conditioning of fruit for 3 days at 37 degrees C prevented chilling injury. The use of suppression subtractive hybridization permitted the isolation of genes differentially expressed in heat-conditioned fruit exposed to chilling conditions, which may be candidates for heat-induced chilling tolerance. Northern blot analysis revealed that some genes were up-regulated by prolonged heat (3 days/37 degrees C) and their expression persisted in fruit cells upon subsequent chilling exposure. The expression of other genes was specifically induced by the combination of heat and cold. Among the putative tolerance-associated genes, we identified two transcription factors of the WRKY family and one TFIIB factor. Heat conditioning also altered the expression of genes encoding proteins involved in secondary metabolism, cell wall modification, oxidative damage and other stress-responsive proteins. These results illustrate the complexity of molecular mechanisms operating during heat-induced chilling tolerance in citrus fruit.
在低温（1.5摄氏度）、非冷冻条件下长期储存会导致福琼柑（Citrus clementina Hort. Ex Tanaka x Citrus reticulata, Blanco）果实发生冷害，表现为出现麻点和褐色凹陷区域，最终可能导致局部细胞死亡。将果实置于37摄氏度下预处理3天可防止冷害。利用抑制性消减杂交技术，分离出了在经过热预处理后再暴露于冷胁迫条件下的果实中差异表达的基因，这些基因可能是热诱导冷耐受性的候选基因。Northern印迹分析表明，一些基因在长时间高温（3天/37摄氏度）处理后上调，并且在随后的冷处理过程中其表达在果实细胞中持续存在。其他基因的表达则是由热和冷的组合特异性诱导的。在假定的与耐受性相关的基因中，我们鉴定出了两个WRKY家族的转录因子和一个TFIIB因子。热预处理还改变了参与次生代谢、细胞壁修饰、氧化损伤和其他应激反应蛋白编码基因的表达。这些结果说明了柑橘果实热诱导冷耐受性过程中分子机制的复杂性。
