Identification of CDPK gene family in yellowhorn (Xanthoceras sorbifolium Bunge) and the role of XsCDPK10 in drought stress tolerance

Yellowhorn ( Xanthoceras sorbifolium Bunge) is a unique woody oil tree species in China, but its growth and yield are severely limited by drought conditions within its distribution area. Research has demonstrated that the calcium-dependent protein kinase (CDPK) gene family plays an important role in regulating plant drought resistance. This study conducted a comprehensive identification and analysis of the CDPK gene family in yellowhorn, identifying a total of 22 CDPK family proteins. XsCDPKs were divided into five subfamilies, with fragment replication acting as the main contributor to the amplification. Expression analysis revealed that XsCDPK10 was significantly upregulated in water-saving germplasm compared with water-consuming germplasm, and its expression was induced by drought conditions. Furthermore, the over-expression of XsCDPK10 enhanced drought tolerance by facilitating ROS clearance and reducing membrane damage in Arabidopsis and yellowhorn. Our research provides a comprehensive and systematic analysis of the CDPK gene family in yellowhorn, and identifies XsCDPK10 as a critical regulatory factor in regulating plant drought resistance, providing new insights into drought resistance mechanism of yellowhorn. • The first comprehensive and systematic analysis of the yellowhron XsCDPK gene family. • Overall response of XsCDPK family to drought stress. • XsCDPK10 positively regulates yellowhorn drought resistance by reducing ROS content.