Genetic mapping, transcriptomic sequencing and metabolic profiling indicated a glutathione S-transferase is responsible for the red-spot-petals in Gossypium arboreum

Abstract

Colored petal spots are correlated with insect pollination e ciency in Gossypium species. However, molecular mechanisms concerning the formation of red spots on Gossypium arboreum owers remain elusive. In the current study, the Shixiya1-R (SxyR, with red spots) × Shixiya1-W (SxyW, without red spots) segregating population was utilized to determine that the red-spot-petal phenotype was levered by a single dominant locus. This phenotype was expectedly related to the anthocyanin metabolites, wherein the cyanidin and delphinidin derivatives constituted the major partition. Subsequently, this dominant locus was narrowed to a 3.27 Mb range on chromosome 7 by genomic resequencing from the two parents and the two segregated progeny bulks that have spotted petals or not. Furthermore, differential expressed genes generated from the two bulks at either of three sequential ower developmental stages that spanning the spot formation were intersected with the annotated ones that allocated to the 3.27 Mb interval, which returned eight genes. A glutathione S-transferase-coding gene (Gar07G08900) out of the eight was the only one that exhibited simultaneously differential expression among all three developmental stages, and it was therefore considered to be the probable candidate. Finally, functional validation upon this candidate was achieved by the appearance of scattered petal spots with inhibited expression of Gar07G08900. In conclusion, the current report identi ed a key gene for the red spotted petal in G. arboretum under the scope of multi-omics approaches, such efforts and embedded molecular resources would bene t future applications underlying the ower color trait in cotton. Key MessageA GST for red-spot-petals in Gossypium arboretum was identi ed as the candidate under the scope of multi-omics approaches.

A glutathione S‐transferase GhTT19 determines flower petal pigmentation via regulating anthocyanin accumulation in cotton

“…Our genetic analysis revealed that the red petals of LR were controlled by a single dominant gene GhTT19 LR . A recent study reported that Gar07G08900 , a GST homologue gene, is responsible for the red‐spot petals in G. arboreum (Zhang et al ., 2022 ). An R2R3‐MYB113 could control base spot formation in Gossypium barbadense (Abid et al ., 2022 ).…”

“…Recent reverse genetic and molecular studies indicated that cotton GST was an essential gene for anthocyanin accumulation in the red leaf of upland cotton (Li et al ., 2020 ; Shao et al ., 2021 ). Also, Gar07G08900 , a GST homologue was responsible for the red‐spot‐petals in Gossypium arboreum (Zhang et al ., 2022 ). However, no forward genetic and genomic study was reported for more details about anthocyanin pigmentation in cotton petals.…”