The transcriptome response of leaves of the resurrection plant, Xerophyta humilis to desiccation

In angiosperms, desiccation tolerance, a genetic trait that enables tissues to survive loss of more than 95% of cellular water is widely observed in the seeds, but is only found in the vegetative tissues of a small group of species known as the resurrection plants. Xerophyta humilis is a small resurrection plant indigenous to Southern Africa. In this study, the hypothesis that vegetative desiccation tolerance is derived from an adaptation of seed desiccation tolerance was tested by characterizing changes in the transcriptome of X. humilis leaves during desiccation. The mRNA transcript abundance of a set of 1680 X. humilis genes was analyzed at 6 different stages of water loss in the leaves of X. humilis. Functional enrichment analysis showed that genes that were down-regulated during desiccation were over-represented with genes involved in photosynthesis, cellular developmental processes, as well as transcription regulator activity. Three distinct clusters of up-regulated genes were identified. The earliest set of up-regulated genes were enriched with genes associated with the turnover of proteins and the simultaneous synthesis of proteins required for protection. Enrichment also included genes associated with lipid body synthesis, as well as the transport of storage proteins to vacuoles. Two groups of late desiccation up-regulated genes were also identified, their expression only increased at later stages of desiccation and remained high in the desiccated leaves.

Grantor dc:publisher.institution

Department of Molecular and Cell Biology

Year dc:date.issued

2014

Author dc:creator

• Shen, Arthur Yen-Hsiang

Advisor dc:contributor.advisor

• Illing, Nicola

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/13009

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/13009