Mechanism of the Mixture of Abscisic Acid and Thidiazuron in Regulating Cotton Leaf Abscission

Abstract

Morphological analysis and RNA-seq were conducted to profile the differentially expressed genes (DEGs) at different time points after treatment with a mixture of ABA and TDZ (AT), a mixture of TDZ and diuron (TD), ABA (A), TDZ (T), or water (W). A total of 2805 DEGs were detected after treatment with A, 18 849 DEGs after treatment with T, 29 822 DEGs after treatment with AT, and 26 446 DEGs after treatment with TD. GO and KEGG analyses revealed the enrichment of functional categories, including plant hormone signal transduction and metabolic pathways, after AT treatment. Ethylene-related genes (ACO3 and ACS) and cytokinin oxidase/dehydrogenase (CKX) were upregulated. Cytokinin response regulatory factors (ARRs) were downregulated, and the cytokinin content was decreased. Gibberellin-related genes (GIDs) were downregulated, and jasmonic-acidrelated genes (JAZ10) were upregulated. The results showed that the interaction between ethylene and CTK regulated cotton leaf defoliation after AT treatment. Significantly, gibberellin and jasmonic acid also played a role in cotton leaf defoliation. The results of this study lay a foundation for further exploration of the function of ABA and TDZ in regulating cotton defoliation.

Genomic insights into CKX genes: key players in cotton fibre development and abiotic stress responses

“…In cotton, recent studies have begun to uncover the multiple roles of CKX genes in physiological processes such as leaf defoliation, fruit branch internode elongation and stress responses ( Naveed et al, 2023 ). Using comprehensive analyses such as RNA-Seq techniques, various studies have shown that CKX genes are upregulated in response to treatments with abscisic acid (ABA) and thidiazuron (TDZ), indicating their involvement in cotton leaf defoliation ( Zhou et al, 2022 ). Transcriptome profiling has also shown that CKX genes are associated with fruit branch elongation in upland cotton ( Ju et al, 2019 ).…”

Transcriptome and targeted hormone metabolome reveal the molecular mechanisms of flower abscission in camellia

“…Similar to endogenous GA, the use of exogenous GA may prevent fruit drop in citrus ( Lal et al., 2015 ; Rokaya et al., 2016 ). Instead, ethylene, abscisic acid (ABA), and methyl jasmonate (MJ) have been shown to enhance shedding in latest research ( Xu et al., 2020 ; Hewitt et al., 2021 ; Zhou et al., 2022 ). Citrus fruit abscission is aided by ethylene, which research shows is concentrated in the abscission zone ( Dutta et al., 2022 ).…”