Chloroplast Small Heat Shock Protein CsHSP24.6 of Tea Plants Positively
Regulates Heat, Light, and Salt Stress Tolerance
Abstract
Small heat shock proteins (sHSPs) function as molecular chaperones,
which play crucial roles in plant growth, development, and stress
response. However, the function of the sHSP gene in the tea plant
(Camellia sinensis L.) has not been extensively investigated. In total,
54 C. Sinensis small heat shock proteins (CssHSPs) in the tea plant
genome were screened. Phylogenetic analysis revealed that CssHSPs in the
same group have similar conserved domains and motifs; conversely,
significant structural differences exist in the different groups. Most
CssHSP genes had tissue-specific expression. They also responded to one
or more abiotic or biotic stresses, CsHSP24.6 was selected for
functional analysis. The results demonstrated that the expression of
CsHSP24.6 increased under abiotic stresses such as temperature, light
intensity, and NaCl. In addition, under high temperature and high light
intensity treatments, CsHSP24.6 and its target gene CspTAC5 interacted
to enhance the heat and light resistances of the plant. CsHSP24.6
facilitates resistance to abiotic stresses in tea plants. These results
further support that CsHSP24.6 plays an essential role in maintaining
plant growth and development under abiotic stress.