Cloning and Expression Analysis of CsHLS2 in Cucumber

Fang Kai; Du Yalin; Hao Ning; Cao Jiajian; Wang Chunhua; Wu Tao

doi:10.14083/j.issn.1001-4942.2026.01.003

Abstract：HLS1 is a key gene regulating plant apical hook formation and is also involved in multiple plant developmental processes.CsHLS1 modulates plant architecture in cucumber by regulating the sizes of leaf and petiole angles.However,whether CsHLS1 has homologs in cucumber and their potential biological func-tions remained to be elucidated.In this study,a protein highly homologous to CsHLS1 was identified in cucum-ber by constructing a phylogenetic tree of CsHLS1,which was designated as CsHLS2.Furthermore,CsHLS2 from cucumber was cloned and its molecular characteristics and expression profiles were investigated.The re-sults showed that the full-length sequence of CsHLS2 was 2 158 bp,encoding 278 amino acids.The CsHLS2 protein had the molecular weight of 32.25,the theoretical isoelectric point of 9.03,the instability index of 9.24,the aliphatic index of 84.17,the grand average of hydropathicity of-0.415,and had no signal peptide or transmembrane domain,indicating that it was a stable protein.The secondary structure of CsHLS2 was mainly composed of random coils(59.71%)and α-helices(26.26%).Phylogenetic analysis and conserved domain analysis revealed that CsHLS2 in cucumber had the closest genetic relationship with CmHLS2 in melon(Cucumis melo).The promoter region of CsHLS2 was cloned and analyzed for its action elements,and the re-sult demonstrated that this region contained multiple environmental and hormone-responsive elements.Quanti-tative real-time PCR(RT-qPCR)analysis indicated that CsHLS2 was highly expressed in cucumber ovaries and petiole bases.These findings could provide a foundation for further elucidating the functional roles of CsHLS2 in cucumber growth and development.