Characterization of Two Ethephon-Induced IDA-Like Genes from Mango, and Elucidation of Their Involvement in Regulating Organ Abscission

Abstract

In mango (Mangifera indica L.), fruitlet abscission limits productivity. The INFLORESCENCE DEFICIENT IN ABSCISSION (IDA) peptide acts as a key component controlling abscission events in Arabidopsis. IDA-like peptides may assume similar roles in fruit trees. In this study, we isolated two mango IDA-like encoding-genes, MiIDA1 and MiIDA2. We used mango fruitlet-bearing explants and fruitlet-bearing trees, in which fruitlets abscission was induced using ethephon. We monitored the expression profiles of the two MiIDA-like genes in control and treated fruitlet abscission zones (AZs). In both systems, qRT-PCR showed that, within 24 h, both MiIDA-like genes were induced by ethephon, and that changes in their expression profiles were associated with upregulation of different ethylene signaling-related and cell-wall modifying genes. Furthermore, ectopic expression of both genes in Arabidopsis promoted floral-organ abscission, and was accompanied by an early increase in the cytosolic pH of floral AZ cells—a phenomenon known to be linked with abscission, and by activation of cell separation in vestigial AZs. Finally, overexpression of both genes in an Atida mutant restored its abscission ability. Our results suggest roles for MiIDA1 and MiIDA2 in affecting mango fruitlet abscission. Based on our results, we propose new possible modes of action for IDA-like proteins in regulating organ abscission.

Cloning and Bioinformatics Analysis of GhArfGAP in Cotton (Gossypium hirsutum) Boll Abscission Layer With Ethylene Treatment

“…At the same time, ethylene can also induce the formation of the abscission layer and can cause the abscission of flowers and fruits. In mango, after ethylene induction, the expression of MiIDA1 and MiIDA2 had upregulated and the formation of the abscission layer was promoted (Rai et al, 2021). In Camellia oleifera, CoIDAs are abscission-associated genes, which can be induced by ethylene and push forward the formation of the abscission layer (Yang et al, 2021).…”

Integrated analysis of the transcriptome and metabolome reveals the molecular mechanism regulating cotton boll abscission under low light intensity

“…In an earlier study, the application of exogenous ETH caused all litchi fruitlets to drop within 4 days of the treatment [ 48 ]. The formation of the abscission layer is promoted by ethylene in both mango [ 49 ] and cotton [ 50 ]. In accordance with these findings, in another study, the abscission layer started to form at 12 h after a treatment with 400 mg/L ethylene treatment of cotton bolls [ 51 ].…”

Reevaluation of ethylene role in Arabidopsis cauline leaf abscission induced by water stress and rewatering

“…These authors reported that the IDA transcript increased in the abscission zone (AZ) of the wilted plants at 40% SWC, and then it was further increased 1 day after rewatering (Patharkar & Walker, 2016). Ethylene was reported to induce ida expression in various plant species (Meir et al, 2019; Rai et al, 2021). The possibility that the increase of the IDA transcript in this system is ethylene‐dependent has not yet been studied.…”

“…Distinct IDA family members of tomato and soybean (Tucker & Yang, 2012), citrus (Estornell et al, 2015), lychee (Ying et al, 2016), oil palm (Tranbarger et al, 2019), yellow lupine (Wilmowicz et al, 2018), and most recently from mango (Rai et al, 2021) were characterized and demonstrated to be involved in organ abscission. It should be noted that the expression of these ida gene family members increased in the above species by ethylene or ethephon application.…”