Submitted to: Book Chapter
Publication Type: Book / chapter
Publication Acceptance Date: 2/20/2002
Publication Date: 12/20/2002
Citation: Xin, Z. 2002. Molecular cloning of ESKIMO1 gene by arabidopsis reveals novel mechanism of freezing tolerance. BOOK CHAPTER. 2002. p. 33-41. Interpretive Summary: This book chapter discussed the molecular cloning of a gene related to freezing tolerance of plants. Characterization of the mutant phenotype of this gene reveals that plants can develop freezing tolerance by multiple pathways. Understanding different pathways by which plants increase their freezing tolerance is essential to design effective combinatorial approaches to reduce freezing injury.
Technical Abstract: Temperate plants develop a greater ability to withstand freezing in response to a period of low, but nonfreezing, temperatures through a complex adaptive process of cold acclimation. Very little is known about the signaling processes by which plants perceive the low-temperature stimulus and transduce it into the nucleus to activate genes needed for increased freezing tolerance. To help understand the signaling processes, we have isolated mutants of Arabidopsis that are constitutively freezing tolerant in the absence of cold acclimation. Freezing tolerance of wild- type Arabidopsis was increased from -5.5 deg C to -12.6 deg C by cold acclimation, whereas the freezing tolerance of eskimo1 (esk1) mutants was -10.6 deg C in the absence of acclimation and -14.8 deg C after cold acclimation. Plants with mutations at the esk1 locus accumulated high levels of proline, a compatible osmolyte, but did not exhibit constitutively-increased expression of several cold-regulated genes activated by CBF transcription factors. ESK1 encodes a novel protein, suggesting the ESK1 may regulate a pathway independent from CBF transcription factors.