Sorghum wax chemistry data

Virtually all land plants are coated in a cuticle, a waxy polyester that prevents nonstomatal water loss and is important for heat and drought tolerance. Here, we describe a likely genetic basis for a divergence in cuticular wax chemistry between Sorghum bicolor, a drought tolerant crop widely cultivated in hot climates, and its close relative Zea mays (maize). Combining chemical analyses, heterologous expression, and comparative genomics, we reveal that: 1) sorghum and maize leaf waxes are similar at the juvenile stage but, after the juvenile-to-adult transition, sorghum leaf waxes are rich in triterpenoids that are absent from maize; 2) biosynthesis of the majority of sorghum leaf triterpenoids is mediated by a gene that maize and sorghum both inherited from a common ancestor but that is only functionally maintained in sorghum; and 3) sorghum leaf triterpenoids accumulate in a spatial pattern that was previously shown to strengthen the cuticle and decrease water loss at high temperatu...几乎所有陆生植物均被角质层（cuticle）所覆盖，该蜡质聚酯类物质可阻止非气孔性水分散失，对于植物的耐热性与耐旱性至关重要。本研究针对在炎热气候下广泛种植的耐旱作物双色高粱（Sorghum bicolor）与其近缘物种玉米（Zea mays）之间的表皮蜡质化学成分差异，阐明了其潜在的遗传基础。本研究结合化学分析、异源表达(heterologous expression)与比较基因组学(comparative genomics)手段，揭示了如下三点：1） 高粱与玉米的叶片蜡质在幼年期性状相似，但在完成幼龄至成年的发育转变后，高粱叶片蜡质中富含玉米所不含的三萜类化合物(triterpenoids)；2） 高粱叶片中大部分三萜类化合物的生物合成，由二者从共同祖先处继承而来的基因介导，但该基因仅在高粱中保留了功能活性；3） 高粱叶片三萜类化合物的空间积累模式此前已被证实可强化角质层结构，并在高温环境下降低水分流失……