Chitinases (EC 3.2.2.14), expressed during the plant-pathogen interaction, are associated with plant defense against pathogens. In the present study, a positive correlation between chitinase activity and sugarcane smut resistance was found.
ScChi (GenBank accession no. KF664180), a Class III chitinase gene, encoded a
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Chitinases (EC 3.2.2.14), expressed during the plant-pathogen interaction, are associated with plant defense against pathogens. In the present study, a positive correlation between chitinase activity and sugarcane smut resistance was found.
ScChi (GenBank accession no. KF664180), a Class III chitinase gene, encoded a 31.37 kDa polypeptide, was cloned and identified. Subcellular localization revealed ScChi targeting to the nucleus, cytoplasm and the plasma membrane. Real-time quantitative PCR (RT-qPCR) results showed that
ScChi was highly expressed in leaf and stem epidermal tissues. The
ScChi transcript was both higher and maintained longer in the resistance cultivar during challenge with
Sporisorium scitamineum. The
ScChi also showed an obvious induction of transcription after treatment with SA (salicylic acid), H
2O
2, MeJA (methyl jasmonate), ABA (abscisic acid), NaCl, CuCl
2, PEG (polyethylene glycol) and low temperature (4 °C). The expression levels of
ScChi and six immunity associated marker genes were upregulated by the transient overexpression of
ScChi. Besides, histochemical assay of
Nicotiana benthamiana leaves overexpressing pCAMBIA 1301-
ScChi exhibited deep DAB (3,3'-diaminobenzidinesolution) staining color and high conductivity, indicating the high level of H
2O
2 accumulation. These results suggest a close relationship between the expression of
ScChi and plant immunity. In conclusion, the positive responses of
ScChi to the biotic and abiotic stimuli reveal that this gene is a stress-related gene of sugarcane.
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