The genes determining synthesis of pigments in cotton

Abstract

Naturally coloured cotton is environmentally friendly, since bleaching and chemical dyeing are not needed during textile production. Studying moleculargenetic mechanisms underpinning pigment production may facilitate breeding cotton with coloured fibre. In the current review we summarize the known data on structural and regulatory genes involved in biosynthesis of flavonoid pigments proanthocyanidins (PAs) in brown and caffeic acid (CA) derivates in green fibre. The first chapter considers the first studies on fibre cotton inheritance, from the beginning of the last century. Then, we briefly review the biochemical and physico-chemical methods proving the presence of PAs in brown fibre and derivatives of CA in green cotton fibre. The biochemical analysis of coloured cotton fibre was followed by genetic studies of structural genes coding for enzymes participating in PAs and CA biosynthesis, transport and oxidation processes. We summarize the data on the genes coding for transcription factors from the MBW (MYB-bHLH-WD40) regulatory complex, which controls flavonoid biosynthesis in coloured cotton fibre. The regulatory gene most interesting as a target for markers-assisted breeding and genome editing is GhTT2-3A.

Transcriptome and Metabolome Profiling Unveil Pigment Formation Variations in Brown Cotton Lines (Gossypium hirsutum L.)

“…Flavonoids are well-known to play a wide range of biological activities in plant UV protection, flower coloration, antioxidant, antibacterial, anti-inflammatories, anti-cancer and antifungal properties, and defense [ 27 ]. Contrary to brown color formation, PAs also have antioxidant and anti-inflammation activities [ 13 ]. NBCC biological activities are understudied.…”

“…In Petunia, floral anthocyanin pigmentation patterns expression patterns were reported to be determined by R2R3-MYB and bHLH activators. In addition, R2R3-MYB proteins activated early anthocyanins and PA biosynthetic genes [ 13 ]. Moreover, some reports have confirmed that MYB encoding TT2 homolog gene GhTT2-3A controls PA biosynthesis and dark brown pigmentation in cotton fiber coloration, and high-level expression of GhTT2_A07 results in the up-regulation of the PA pathway [ 17 ].…”

“…The structural content of PAs has been reported in both white and brown fibers. However, Mikhailova et al further explained that prodelphinidin and PA contents are equal in white cotton, but in brown, 90% of prodelphinidin in comparison to 10% PA was found [ 13 ]. Chemically, PAs are colorless polymers that are synthesized by adding flavan-3, 4-diol molecules to an initiating flavan-3-ol unit via the flavonoid pathway [ 11 , 14 ].…”