Laboratory of Plant Physiology, Wageningen University, Droevendaalsesteeg 1, 6708PB Wageningen, The Netherlands.
Department of Molecular and Cell Biology, University of Cape Town, Private Bag, 7701 Cape Town, South Africa.
Nat Plants. 2017 Mar 27;3:17038. doi: 10.1038/nplants.2017.38.
Desiccation tolerance is common in seeds and various other organisms, but only a few angiosperm species possess vegetative desiccation tolerance. These 'resurrection species' may serve as ideal models for the ultimate design of crops with enhanced drought tolerance. To understand the molecular and genetic mechanisms enabling vegetative desiccation tolerance, we produced a high-quality whole-genome sequence for the resurrection plant Xerophyta viscosa and assessed transcriptome changes during its dehydration. Data revealed induction of transcripts typically associated with desiccation tolerance in seeds and involvement of orthologues of ABI3 and ABI5, both key regulators of seed maturation. Dehydration resulted in both increased, but predominantly reduced, transcript abundance of genomic 'clusters of desiccation-associated genes' (CoDAGs), reflecting the cessation of growth that allows for the expression of desiccation tolerance. Vegetative desiccation tolerance in X. viscosa was found to be uncoupled from drought-induced senescence. We provide strong support for the hypothesis that vegetative desiccation tolerance arose by redirection of genetic information from desiccation-tolerant seeds.
耐旱性在种子和各种其他生物中很常见，但只有少数被子植物物种具有营养体耐旱性。这些“复苏物种”可能成为设计具有增强耐旱性作物的理想模型。为了了解赋予营养体耐旱性的分子和遗传机制，我们为复苏植物 Xerophyta viscosa 生成了高质量的全基因组序列，并评估了其脱水过程中的转录组变化。数据揭示了与种子耐旱性相关的典型转录物的诱导，以及 ABI3 和 ABI5 同源物的参与，这两者都是种子成熟的关键调节剂。脱水导致基因组“脱水相关基因簇”（CoDAGs）的转录物丰度增加，但主要是减少，反映了生长停止，从而允许表达耐旱性。在 X. viscosa 中，营养体耐旱性与干旱诱导的衰老脱钩。我们为这样的假设提供了强有力的支持，即营养体耐旱性是通过将来自耐旱种子的遗传信息重新定向而产生的。
