Genome investigation suggests MdSHN3, an APETALA2-domain transcription factor gene, to be a positive regulator of apple fruit cuticle formation and an inhibitor of russet development.
Genome investigation suggests MdSHN3, an APETALA2-domain transcription factor gene, to be a positive regulator of apple fruit cuticle formation and an inhibitor of russet development.
复制标题
DOI：
10.1093/jxb/erv366
复制
发表时间：
2015-11
影响因子：
6.9
通讯作者：
Costa F
中科院分区：
文献类型：
--
作者：
Lashbrooke J;Aharoni A;Costa F
对苹果群体的QTL分析确定了与角质层形成和随后的黄褐斑形成相关的基因组区域。进一步的研究表明，MdSHN3是苹果角质层生物合成的主要调控因子。苹果果实的外层被一层保护性角质层覆盖。角质层由嵌入蜡的聚合角质基质组成，是一种天然的防水屏障，可以抵御几种非生物和生物压力。就苹果生产而言，角质层是维持采后长期贮藏的关键，而角质层的严重破坏可能会导致一种被称为黄褐斑的疾病的形成。苹果赤霉病是角质层微裂解和木栓质胶合层形成的结果。这通常是一种不受欢迎的消费者特征，并对苹果收获后的储存产生负面影响。为了找出控制苹果角质层生物合成的遗传因素，对苹果全同胞群体进行了数量性状基因座(QTL)定位。鉴定出位于第2和第15染色体上的两个与锈病相关的基因组区域。通过一种新颖的、高通量的皮肤拉伸分析，发现了角质层受损的苹果，而组织学分析证实，在子代中有角质层受损。对确定的QTL区域的进一步基因组研究发现了一组与角质层生物合成有关的潜在基因。通过实时定量聚合酶链式反应对子代的候选基因表达谱分析，突出了15号染色体上SHN1/WIN1转录因子基因(称为MdSHN3)的特异表达模式。SHN1/WIN1的同源基因已被证明调节拟南芥、番茄和大麦的角质层形成。MdSHN3转录因子基因在角质层形成不良的品系中表达极低，可能是苹果果实角质层生物合成的基本调节因子。
QTL analysis of an apple population identifies genomic regions linked to cuticle formation and subsequent russet formation. Further investigation suggests that MdSHN3 is a major regulator of cuticle biosynthesis in apple. The outer epidermal layer of apple fruit is covered by a protective cuticle. Composed of a polymerized cutin matrix embedded with waxes, the cuticle is a natural waterproof barrier and protects against several abiotic and biotic stresses. In terms of apple production, the cuticle is essential to maintain long post-harvest storage, while severe failure of the cuticle can result in the formation of a disorder known as russet. Apple russet results from micro-cracking of the cuticle and the formation of a corky suberized layer. This is typically an undesirable consumer trait, and negatively impacts the post-harvest storage of apples. In order to identify genetic factors controlling cuticle biosynthesis (and thus preventing russet) in apple, a quantitative trait locus (QTL) mapping survey was performed on a full-sib population. Two genomic regions located on chromosomes 2 and 15 that could be associated with russeting were identified. Apples with compromised cuticles were identified through a novel and high-throughput tensile analysis of the skin, while histological analysis confirmed cuticle failure in a subset of the progeny. Additional genomic investigation of the determined QTL regions identified a set of underlying genes involved in cuticle biosynthesis. Candidate gene expression profiling by quantitative real-time PCR on a subset of the progeny highlighted the specific expression pattern of a SHN1/WIN1 transcription factor gene (termed MdSHN3) on chromosome 15. Orthologues of SHN1/WIN1 have been previously shown to regulate cuticle formation in Arabidopsis, tomato, and barley. The MdSHN3 transcription factor gene displayed extremely low expression in lines with improper cuticle formation, suggesting it to be a fundamental regulator of cuticle biosynthesis in apple fruit.