Identification and Expression Characteristics of the Cryptochrome Gene Family in Chimonobambusa sichuanensis

Cryptochrome is an important class of blue-light receptors involved in various physiological activities such as photomorphogenesis and abiotic stress regulation in plants. In order to investigate the molecular mechanism of blue-light-induced color change in <i>Chimonobambusa sichuanensis</i>, we screened and cloned the gene encoding the blue-light receptor Cryptochrome. In order to investigate the molecular mechanism of blue-light-induced color change in <i>Chimonobambusa sichuanensis</i>, we screened and cloned the gene encoding the blue-light receptor Cryptochrome in <i>Ch.sichuanensis</i>, and analyzed the expression characteristics of the Cryptochrome gene in <i>Ch.sichuanensis</i> under different light intensities, light quality, and temperatures by qRT-PCR. Through homologous cloning, a total of four <i>CsCRY</i> genes were obtained in the <i>Ch.sichuanensis</i> genome, namely, <i>CsCRY1a</i>, <i>CsCRY1b</i>, <i>CsCRY2</i>, and <i>CsCRY3</i>. Structural domain analyses of the encoded proteins of the four genes revealed that all CsCRYs proteins had the typical photoreceptor structural domain, PRK (protein kinase C-related kinase). Phylogenetic tree analyses revealed that the four genes <i>CsCRY1a</i>, <i>CsCRY1b</i>, <i>CsCRY2</i>, and <i>CsCRY3</i> could be categorized into three subfamilies, with <i>CsCRY1a</i> and <i>CsCRY1b</i> clustered in subfamily I, <i>CsCRY2</i> classified in subfamily II, and <i>CsCRY3</i> belonging to subfamily III. All CsCRYs proteins lacked signal peptides and the instability index was higher than 40, among which the isoelectric points of <i>CsCRY1a</i>, <i>CsCRY1b</i>, and <i>CsCRY2</i> were around five. qRT-PCR analysis revealed that the expression of all four <i>CsCRYs</i> genes was up-regulated at 75 µmol·m^-2·s^-1 blue-light illumination for 4 h. In addition, under treatments of different light quality, the expression of <i>CsCRY2</i> genes was significantly higher under blue light than under red light and a mixture of red light and blue light with a light intensity of 1:1; the expression of <i>CsCRY1a</i> and <i>CsCSY1b</i> was significantly higher in the mixed light of red and blue light than in the single light treatment, while under different temperature gradients, <i>CsCRYs</i> genes were highly expressed under low-temperature stress at -5 °C and 0 °C. This study provides a basis for further research on blue-light-induced color change in <i>Ch.sichuanensis</i> and expands the scope of Cryptochrome gene research.