Reference "A leaf-specific gene stimulated by light during wheat acclimation to low temperature"

Reference ID

9248

Title

A leaf-specific gene stimulated by light during wheat acclimation to low temperature

Source

Plant molecular biology, 1993, vol. 23, pp. 255-265

Authors (3)

Chauvin-L-P	Houde-M
Sarhan-F

Abstract

We report here the identification and characterization of a new leaf-specific
light-stimulated gene induced during cold acclimation of wheat. Sequence
analysis revealed that the gene encodes a protein of 19 kDa with a pI of 8.8.
This is a novel protein with a particular charge distribution. The C-terminal
half has a high propensity to form an alpha-helix and contains all the acidic
amino acids with a net negative charge of -7. On the other hand, the N-terminal
half is rich in proline, lysine and arginine with a net positive charge of +10.
These properties are commonly found in several transcription factors. The
protein is also rich in alanine (21%), is hydrophilic but not boiling soluble
in contrast to other alanine-rich proteins. During low temperature exposure,
the corresponding mRNA accumulates rapidly in the leaf and remains at a
constant level in two tolerant cultivars used. However, in a less tolerant
cultivar, the mRNA level declines despite maintaining the plants at 4 degrees
C. Southern blot analysis indicates that the differential expression in the
less tolerant genotype is not due to a different genomic organization or gene
copy number. The mRNA was specifically localized in leaf tissues and increased
several-fold during the greening at 4 degrees C. Furthermore, this gene is not
induced in callus cultures acclimated in the absence or presence of light. This
suggests that the full expression of this gene is dependent on organized leaf
tissue. The expression of this gene was not affected by ABA, drought, heat
shock, salinity, wounding or anaerobiosis, demonstrating that it is
specifically induced by low temperature. The Wcs19 mRNA is preferentially
expressed in tolerant Gramineae species.