The CsTM alters multicellular trichome morphology and enhances resistance against aphids by interacting with CsTIP1;1 in cucumber

Authors: YANG, SONGLING - China Agricultural University; XUE, SHDAN - China Agricultural University; SHAN, LI - China Agricultural University; FAN, SHANSHAN - China Agricultural University; SUN, LEI - China Agricultural University; DONG, YUMING - China Agricultural University; LI, SEN - China Agricultural University; GAO, YIMING - China Agricultural University; QI, YU - China Agricultural University; YANG, LIN - China Agricultural University; AN, MENGHANG - China Agricultural University; WANG, FANG - China Agricultural University; PANG, JINAN - Tianjing Deit Seeds Inc; ZHANG, WENZHU - Tianjing Deit Seeds Inc; Weng, Yiqun; LIU, XINGWANG - China Agricultural University; REN, HUAZHONG - China Agricultural University

Submitted to: Journal of Advanced Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/9/2024
Publication Date: 4/10/2024
Citation: Yang, S., Xue, S., Shan, L., Fan, S., Sun, L., Dong, Y., Li, S., Gao, Y., Qi, Y., Yang, L., An, M., Wang, F., Pang, J., Zhang, W., Weng, Y., Liu, X., Ren, H. 2024. The CsTM alters multicellular trichome morphology and enhances resistance against aphids by interacting with CsTIP1;1 in cucumber. Journal of Advanced Research. 2090-1232/
2023. https://doi.org/10.1016/j.jare.2024.04.008.
DOI: https://doi.org/10.1016/j.jare.2024.04.008

Interpretive Summary: Background Trichomes are hairy structure on the surface of above-ground plant organs that may play important roles in defense against biotic and abiotic stresses. In cucumber, the presence or absence of fruit spines (trichomes) is an important fruit quality trait for some market groups. The molecular mechanisms of fruit spine development are largely unknown. Major findings In this study, the fruit spines in three cucumber lines with normal (wild type) and abnormal (in a mutant) spines were investigated. Compared with normal cucumbers, the mutant fruit spines are soft which do not give people a prickly sensation when touching, but is more susceptible to environment stresses. We cloned the gene called CsTM that is responsible for the mutation which encodes a C-lectin receptor-like kinase. A single nucleotide mutation inside the gene results in deletion of part of the coding region (the first exon) in the mutant. CsTM was highly expressed in ovaries and leaves. CRISPR/Cas9-based gene editing of the gene resulted in similar fruit spine appearance as seen in the mutant. Silencing of the gene causes fruit spines shorter and sparser. We identified a protein CsTIP1;1 that can interact with CsTM, which facilitates transportation of H2O2. We suggest that H2O2 can act as a signal molecule to activate downstream responses to regulate trichome differentiation. Significance This work identifies a novel mechanism that CsTM-CsTIP1;1 module integrates H2O2 signal for trichome development in cucumber. This may be of interest to molecular biologists who study trichome morphogenesis.

Technical Abstract: Trichomes are hairy structure on the surface of above-ground plant organs that may play important roles in defense against biotic and abiotic stresses. In cucumber, the presence or absence of fruit trichomes or spines is also important quality trait for some market groups. In this study, we examined the fruit spines in three cucumber lines ('3542', '3407' and '6102-7') with normal trichomes (wild type) and a spontaneous mutant line '3541' with morphologically abnormal trichomes. The mutant was name Trichome Morphology (CsTM). Compared with the wildtype, the mutant trichome cells had a higher base and a smaller area connecting with the pericarp than that in wild type, which resulted in a soft touch feeling and more susceptible to environment stresses. Map-based cloning of the mutant allele identified a candidate gene for CsTM that encodes a C-lectin receptor-like kinase. A single nucleotide mutation in the intron resulted in deletion of the first exon in the mutant. CsTM was highly expressed in ovaries and leaves. Knockout of CsTM by CRISPR/Cas9-based gene editing resulted in taller base in fruit spines. In gene silenced plants, the trichomes became shorter and sparser. Yeast library screening and in vitro kinase assays revealed that CsTM was able to interact with and phosphorylate CsTIP1;1, an aquaporin that highly expressed in ovaries. This interaction contributed to facilitate transportation of H2O2, which acts as signal molecule to activate downstream responses, ultimately regulating trichome differentiation. This work identifies a novel mechanism that CsTM-CsTIP1;1 module integrates H2O2 signal for trichome development in cucumber.