AtchitIV gene expression is stimulated under abiotic stresses and is spatially and temporally regulated during embryo development

Abstract

The expression of AtchitIV gene was analysed in Arabidopsis plants submitted to abiotic stresses. Transcript accumulation was detected in leaves in response to UV light exposure, exogenous salicylic acid administration and wounding. Transgenic Arabidopsis plants carrying AtchitIV promoter::gus fusion also showed differential expression of the reporter gene in response to these treatments. The AtchitIV expression was also analysed during Arabidopsis embryo development. GUS assay demonstrated AtchitIV promoter activation in zygotic embryos from torpedo stage up to full maturation. Promoter deletion analysis indicated that all the 5' cis-acting elements responsible for the specific tissue expression are located in a region of 1083 bp, adjacent to the start of transcription. A negative regulatory region located between portions -1083 and -600 was also observed.

The Capsicum annuum class IV chitinase ChitIV interacts with receptor-like cytoplasmic protein kinase PIK1 to accelerate PIK1-triggered cell death and defence responses

“…Plant class IV chitinases are mainly involved in regulating resistance to fungal pathogens ( Hietala et al , 2004 ). There is some evidence that class IV chitinases are implicated in other processes, such as the response to abiotic stress ( Gerhardt et al , 2004 ) and defence against bacterial pathogens ( Gerhardt et al , 1997 ). However, our knowledge of the cellular mechanisms by which class IV chitinases activate plant cell death and innate immunity is still limited, and functional studies of class IV chitinases are needed to provide evidence for their distinct functions.…”

Identification, Phylogeny and Transcript of Chitinase Family Genes in Sugarcane

“…Plant chitinase genes have been grouped into seven classes (class I~VII), suggesting that chitinase isozymes were encoded by a multi-gene family 16 17 18 . A variety of chitinase family genes involved in pathogen attack 19 20 , hormone application 21 , temperature change 22 , high salt content 22 , metal and wounding stresses 23 , have been cloned and characterized from various plants such as Arabidopsis thaliana 24 , Nicotiana tabacum 25 , Oryza sativa 26 , Triticum aestivum 17 and Sorghum bicolor 27 . A class I chitinase isolated from Hordeum vulgare has been reported to demonstrate antifungal activity 28 .…”

“…Many chitinase genes are developmentally regulated and may play a part in the specific physiological processes 32 . The expression of AtchitIV gene was analyzed in Arabidopsis exposed to abiotic stress by Gerhardt et al 23 . Transcripts accumulation was detected in leaves in response to UV light exposure, exogenous SA administration and wounding.…”

“…Transcripts accumulation was detected in leaves in response to UV light exposure, exogenous SA administration and wounding. The AtchitIV expression was also analyzed during Arabidopsis embryo development 23 .…”

Truncation of class IV chitinases from Arabidopsis by secreted fungal proteases

“…As fungal hyphae contain chitin, class IV chitinases may either inhibit the growth of fungal hyphae (Huynh et al ., 1992; Schlumbaum et al ., 1986) or cleave chitin fragments from hyphae to produce signalling molecules that induce plant defences (Kaku et al ., 2006). However, evidence that some class IV chitinases are involved in other processes—response to abiotic stress (Gerhardt et al ., 2004), defence against bacterial pathogens (Gerhardt et al ., 1997), embryogenesis (De Jong et al ., 1992; Wiweger et al ., 2003)—has also been reported. It is therefore likely that biochemical and functional studies of class IV chitinases will reveal the existence of subclasses with distinct functions.…”