Recently, a research paper entitled “A plastid lipid associated protein encoding gene (GhPAP) that positively regulates fiber strength was identified via genetic mapping and transcriptomic analysis of a stable QTL on chromosome D06 of upland cotton” was published online in Theoretical and Applied Genetics(IF=4.4, zone 1 of agriculture and forestry sciences, TOP journal) by molecular breeding laboratory of Institute of Cotton, HAAFS. This study reveals that GhPAP gene may regulate the cotton fiber strength by regulating cell wall thickness and fiber helix formation.
Fiber strength(FS), length(FL) and fineness of cotton are key traits that determine fiber quality. Although multiple genes related to fiber quality have been identified, the molecular mechanisms have not been fully clarified yet. In this study, an FS/FL-related QTL was mapped to a 2.92 Mb region(containing 81 coding genes) on chromosome D06 by combining SLAF-BSA-seq and InDel analyses. During the process of fiber development, five genes in the region were differentially expressed in the near-isogenic lines, Adh (with long and strong fibers) and Adl (with short and weak fibers). Among them, GhPAP(Ghi_D06G06106) was confirmed as a key candidate gene through sequence and functional analysis. The VIGS experiment indicated that decreased GhPAP expression led to a reduction of fiber helix formation and cell wall thickness, and a significant decrease in fiber strength. Among the four cotton lines with distinct genetic backgrounds, the decreased GhPAP expression could significantly reduce the fiber strength. A KASP molecular marker was developed based on SNP loci significantly related to FS/FL in the GhPAP promoter region. In conclusion, this study provides new genetic resources for the improvement of cotton fiber quality.
ZHANG Sujun is the first author and ZHANG Jianhong is the corresponding author of this paper.
Link of this paper: https://doi.org/10.1007/s00122-025-04922-y
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