Chitinase Genes Responsive to Cold Encode Antifreeze Proteins in Winter Cereals

Abstract

Antifreeze proteins similar to two different chitinases accumulate during cold acclimation in winter rye (Secale cereale). To determine whether these cold-responsive chitinases require post-translational modification to bind to ice, cDNAs coding for two different full-length chitinases were isolated from a cDNA library produced from cold-acclimated winter rye leaves. CHT9 is a 1,193-bp clone that encodes a 31.7-kD class I chitinase and CHT46 is a 998-bp clone that codes for a 24.8-kD class II chitinase. Chitinase-antifreeze proteins purified from the plant were similar in mass to the predicted mature products of CHT9 and CHT46, thus indicating that there was little chemical modification of the amino acid sequences in planta. To confirm these results, the mature sequences of CHT9 and CHT46 were expressed in Escherichia coli and the products of both cDNAs modified the growth of ice. Transcripts of both genes accumulated late in cold acclimation in winter rye. Southern analysis of winter rye genomic DNA indicated the presence of a small gene family homologous to CHT46. In hexaploid wheat, CHT46 homologs mapped to the homeologous group 1 chromosomes and were expressed in response to cold and drought. We conclude that two novel cold-responsive genes encoding chitinases with ice-binding activity may have arisen in winter rye and other cereals through gene duplication.

Microspore embryogenesis in barley: anther pre-treatment stimulates plant defence gene expression

“…Besides their developmental regulation, the expression of genes encoding PR proteins is also stimulated by pathogens and by abiotic stresses such as drought, salinity, wounding or elicitor treatments (Thomma et al 1998;Yeh et al 2000). Our study confirms that abiotically stressed anthers of barley also react by inducing PR gene expression.…”

The effects of cold-hardening and Microdochium nivale infection on oxidative stress and antioxidative protection of the two contrasting genotypes of winter triticale

“…A potential role in the defence response against M. nivale infection was previously proposed for unspecific catalase and peroxidase [10] as well as chitinase [14] in winter triticale; chitinase, endochitinase and 1,3-β glucanase in winter rye [15,16]; and chitinase, endochitinase, 1,3-β glucanase, PR1-a protein, peroxidase [17] and thaumatin-like proteins in winter wheat [18]. Gołębiowska and Wędzony [4] proposed two model winter triticale cultivars for triticale-fungus interaction research: partly pink snow mould-resistant Hewo and susceptible Magnat.…”

Diverse chitinases are invoked during the activity-dormancy transition in spruce

“…Chitinases from several species have been shown to play a role in cold and freezing acclimation, with some of these having demonstrated antifreeze activity (e.g., Griffith et al 1997;Yeh et al 2000;Pihakaski-Maunsbach et al 2001;Kikuchi and Masuda 2009;Jarząbek et al 2009). Chitinases with demonstrated antifreeze activity from V. corymbosum (class II) and S. cereale (class I and II) are present in cluster 2 (Yeh et al 2000;Kikuchi and Masuda 2009). Cluster 2 also contains PgGQ0183_A06.2 (class I), Pg_GQ03904_P01.1 (class I), Pg_GQ03703_O09.1 (class II), and Pg_GQ03902_B01.1 (class II).…”

“…I t i s p o s s i b l e t h a t P g _ G Q 0 3 9 0 2 _ B 0 1 . 1 a n d Pg_GQ03803_J20.1 require sub-zero temperatures for upregulation and that these chitinases act in complementary timeframes during winter (Hon et al 1995;Yeh et al 2000).…”

“…Chitinases can also act as antifreeze proteins. Some of the first studies recognizing the potential of chitinases to adsorb to ice-forming surfaces in cold acclimation processes were carried out in winter rye and other cereals (Hon et al 1995;Griffith et al 1997;Yeh et al 2000;PihakaskiMaunsbach et al 2001). Chitinases with antifreeze activity have been isolated from apoplastic spaces of needles from overwintering Pseudotsuga menziesii (Mirb.)…”