Over‐expression of GhUGP1 in upland cotton improves fibre quality and reduces fibre sugar content

Abstract

GhUGP1 (cotton uridine diphosphate glucose pyrophosphorylase) is one of the most highly expressed genes and proteins in fast elongation cotton fibres. The objective of this study was to determine whether fibre quality and reduced sugar content could be improved in fibres by over-expressing GhUGP1 in cotton plants under conditions of low autumn temperatures and large diurnal temperature differences. A plant GhUGP1 vector was constructed and introduced into the 3-6-7 cotton line using agrobacterium-mediated transformation. Following selection with kanamycin sulphate and polymerase chain reaction (PCR) and Southern blotting analyses, three independent homozygous transgenic lines were selected for molecular and chemical study. Compared with wild type, the transcriptional activity of GhUGP1 was higher and more long lasting in the transgenic lines. Fibres were longer and stronger, soluble and reduced sugar levels were significantly decreased, and cellulose levels were significantly increased. In addition, plant height also increased by 40.1-45.1%. These results demonstrate that GhUGP1 expression was considerably increased in the transgenic plants, accelerating the conversion of oligosaccharides to polysaccharides in the developing cotton fibre.

Overexpression of a Sucrose Synthase Gene Indirectly Improves Cotton Fiber Quality Through Sucrose Cleavage

“…These results clearly demonstrate a role for SuS in fiber elongation and secondary wall biosynthesis in addition to its role in the early stages of cotton fiber development, in accordance with previous report in which this gene has been found to play an essential part in early (-2 to 5 DPA) cotton fiber development (Ahmed et al, 2019). Moreover, the SuS expression pattern in the transgenic cotton plants at 8, 15, and 20 DPA, positively linked with SuS activity, reflects the role of this gene in fiber elongation, as previously reported by the overexpression of GhSuSA1 and GhUGP1 under CaMV35S promoter (Jiang et al, 2012;Li et al, 2015).…”

Stable transformation and expression of GhEXPA8 fiber expansin gene to improve fiber length and micronaire value in cotton

“…Transgenic plant lines 1 ( GhEXPA8-1 ) and 2 ( GhEXPA8-4 ), respectively produced 50% and 20% more cellulose than the control plants, as shown in Figure 6 . Similar results of improvement of cellulose content of transgenic cotton plant were presented by Li et al ( 2015 ), Wang et al ( 2009 ), and Teixeira et al ( 2010 ).…”

“…Similar results of improvement in fiber strength were also reported by Jiang et al ( 2000 ). All of the transgenic plants showed improvement in fiber length (20%) and micronaire value (19.10%) with consistently higher fiber lengths and micronaire values in each generation (Figures 7A,C ), which has been observed in previous studies (Luo et al, 2007 ; Machado et al, 2009 ; Zhang et al, 2010 ; Qin and Zhu, 2011 ; Li et al, 2015 ).…”

Comparative analysis of Constitutive and fiber-specific promoters under the expression pattern of Expansin gene in transgenic Cotton

“…These results are in accordance with the previously reported data where the Expansin gene was found to significantly increase the cellulose quantity in transgenic fiber. Cellulose deposition has a direct correlation with Expansin gene expression as cell wall loosening and tightening during the elongation phase, creating slipping of cellulose fibrils and eventually creates enough room for cellulose deposition [28,32,33]. An increase in cellulose content of transgenic varieties can be linked with the cell wall…”