Fisher Kirsten M
National Evolutionary Synthesis Center, 2024 West Main Street Suite A200, Durham, North Carolina 27705 USA.
Am J Bot. 2008 Apr;95(4):506-15. doi: 10.3732/ajb.95.4.506.
Desiccation tolerance is a complex trait that is broadly but infrequently present throughout the evolutionary tree of life. Desiccation tolerance has played a significant role in land plant evolution, in both the vegetative and reproductive life history stages. In the land plants, the late embryogenesis abundant (LEA) gene families are involved in both abiotic stress tolerance and the development of reproductive propagules. They are also a major component of vegetative desiccation tolerance. Phylogenies were estimated for four families of LEA genes from Arabidopsis, Physcomitrella, and the desiccation tolerant plants Tortula ruralis, Craterostigma plantagineum, and Xerophyta humilis. Microarray expression data from Arabidopsis and a subset of the Physcomitrella LEAs were used to estimate ancestral expression patterns in the LEA families and to evaluate alternative hypotheses for the origins of vegetative desiccation tolerance in the flowering plants. The results contradict the idea that vegetative desiccation tolerance in the resurrection angiosperms Craterostigma and Xerophyta arose through the co-option of genes exclusively related to stress tolerance, and support the propagule-derived origin of vegetative desiccation tolerance in the resurrection plants.
耐干燥能力是一种复杂的性状，在整个生命进化树中广泛但不常见。耐干燥能力在陆地植物进化的营养和生殖生活史阶段都发挥了重要作用。在陆地植物中，晚期胚胎发生丰富（LEA）基因家族既参与非生物胁迫耐受性，也参与生殖繁殖体的发育。它们也是营养耐干燥能力的主要组成部分。对来自拟南芥、小立碗藓以及耐干燥植物土生扭口藓、车前叶景天和旱生萱草的四个LEA基因家族进行了系统发育分析。利用拟南芥和小立碗藓部分LEA基因的微阵列表达数据来估计LEA家族的祖先表达模式，并评估开花植物营养耐干燥能力起源的替代假说。结果与复活被子植物车前叶景天和旱生萱草的营养耐干燥能力是通过专门与胁迫耐受性相关的基因的共同选择产生的观点相矛盾，并支持复活植物营养耐干燥能力源自繁殖体的观点。
