Genome-Wide Identification and Expression Analyses of the Chitinases under Cold and Osmotic Stress in Ammopiptanthus nanus

Abstract

Chitinase is a kind of hydrolase with chitin as a substrate and is proposed to play an essential role in plant defense system by functioning against fungal pathogens through degrading chitin. Recent studies indicated chitinase is also involved in abiotic stress response in plants, helping plants to survive in stressful environments. A. nanus, a rare evergreen broad-leaved shrub distrusted in deserts in Central Asia, exhibits a high level of tolerance to drought and low temperature stresses. To identify the chitinase gene involved in drought and low temperature responses in A. nanus, we performed genome-wide identification, classification, sequence alignment, and spatio-temporal gene expression analysis of the chitinases in A. nanus under osmotic and low temperature stress. A total of 32 chitinase genes belonging to glycosyl hydrolase 18 (GH18) and GH19 families were identified from A. nanus. Class III chitinases appear to be amplified quantitatively in A. nanus, and their genes carry less introns, indicating their involvement in stress response in A. nanus. The expression level of the majority of chitinases varied in leaves, stems, and roots, and regulated under environmental stress. Some chitinases, such as EVM0022783, EVM0020238, and EVM0003645, are strongly induced by low temperature and osmotic stress, and the MYC/ICE1 (inducer of CBF expression 1) binding sites in promoter regions may mediate the induction of these chitinases under stress. These chitinases might play key roles in the tolerance to these abiotic stress in A. nanus and have potential for biotechnological applications. This study provided important data for understanding the biological functions of chitinases in A. nanus.

Characterization of the Chitinase Gene Family in Mulberry (Morus notabilis) and MnChi18 Involved in Resistance to Botrytis cinerea

“…The phylogenetic analysis of the 31 chitinase sequences was carried out using the neighbor-joining method ( Figure 1 ), and five types of chitinase proteins were identified, which was consistent with the previous Ammopiptanthus nanus chitinases [ 37 ]. The mulberry chitinase genes were divided into two large branches: one was composed of Classes I, II and IV, and the other was composed of Classes III and V.…”

“…We identified a chitinase gene family in M. notabilis ( Table 1 and Figure 1 ), for which a total of 26 mulberry chitinase genes were identified. Compared with the number of chitinase genes in other plants, mulberry is relatively small, but more than Arabidopsis [ 37 ]. This indicates that during the evolution process, the chitinase genes of mulberry have not been significantly amplified.…”

Genome-Wide Analysis of Gene Expression Provides New Insights into Waterlogging Responses in Barley (Hordeum vulgare L.)

“…In soybean roots, the α/β-hydrolase superfamily proteins Glyma06g44990 and Glyma12g12800 were increased in response to flooding stress, after a 2-day flooding treatment [50]. The Xylanase inhibitor protein gene encodes the Glyco_hydro_18 domain-containing protein that is involved in osmotic and low temperature stress responses in plants, helping them to survive in stressful environments [51]. The highly up-regulated Serine carboxypeptidase-like protein gene OsBISCPL1 has a similar domain in rice and was reported to be involved in regulation of defense responses against pathogen infection and oxidative stress [52].…”

Transferability and Polymorphism of SSR Markers Located in Flavonoid Pathway Genes in Fragaria and Rubus Species

“…It is a relatively small group, but it is present in highly consumed fruits [75]. Chitinases can be divided into five classes (I-V), and plant class III chitinases (PR-8 proteins) have an additional lysozyme activity, which is not found in other classes of chitinases [76]. Marzban et al [33] identified four allergen proteins including class III chitinase in raspberry fruits.…”