Differentiation in the genetic basis of stem trichome development between cultivated tetraploid cotton species

Abstract

Background Cotton stem trichomes and seed fibers are each single celled structures formed by protrusions of epidermal cells, and were found sharing the overlapping molecular mechanism. Compared with fibers, cotton stem trichomes are more easily observed, but the molecular mechanisms underlying their development are still poorly understood. Results In this study, Gossypium hirsutum (Gh) and G. barbadense (Gb) were found to differ greatly in percentages of varieties/accessions with glabrous stems and in trichome density, length, and number per trichopore. Gh varieties normally had long singular and clustered trichomes, while Gb varieties had short clustered trichomes. Genetic mapping using five F2 populations from crosses between glabrous varieties and those with different types of stem trichomes revealed that much variation among stem trichome phenotypes could be accounted for by different combinations of genes/alleles on Chr. 06 and Chr. 24. The twenty- six F1 generations from crosses between varieties with different types of trichomes had varied phenotypes, further suggesting that the trichomes of tetraploid cotton were controlled by different genes/alleles. Compared to modern varieties, a greater proportion of Gh wild accessions were glabrous or had shorter and denser trichomes; whereas a smaller proportion of Gb primitive accessions had glabrous stems. A close correlation between fuzz fiber number and stem trichome density was observed in both Gh and Gb primitive accessions and modern varieties. Conclusion Based on these findings, we hypothesize that stem trichomes evolved in parallel with seed fibers during the domestication of cultivated tetraploid cotton. In addition, the current results illustrated that stem trichome can be used as a morphological index of fiber quality in cotton conventional breeding.

Mapping and Detection of Genes Related to Trichome Development in Black Gram (Vigna mungo (L.) Hepper)

“…24 in cotton [ 10 ]. GoSTR , a homolog of GL2-interacting repressors AtGIR1 and AtGIR2 , encodes a hypothetical protein with only 84 amino acids, which inhibits the long hairs to form in cotton stem [ 12 ]. Overexpression of SlCycB2 , the tomato homolog of AtGIR2 , was found to cause the glabrous stems of tomato [ 24 ].…”

“…There are QTLs related to trichome that have been reported in different species. One QTL was demonstrated to control both predatory mite abundance and leaf trichomes in Vitis [ 7 ], while three QTLs related to stem trichome were observed in cotton [ 12 ]. In soybean ( Glycine max L.), a total of 10 and 9 QTLs for trichome length and density were identified, respectively, and three and four candidate genes were estimated, respectively [ 13 ].…”

SDG26 Is Involved in Trichome Control in Arabidopsis thaliana: Affecting Phytohormones and Adjusting Accumulation of H3K27me3 on Genes Related to Trichome Growth and Development

“…Usually, unicellular trichomes have a simple structure without glands. Most angiosperms, some gymnosperms, and bryophytes are non-glandular trichomes [11]. Trichomes also have a significant impact on the quality and yield of commercial crops.…”

GoSTR, a negative modulator of stem trichome formation in cotton

“…Although Arabidopsis leaf trichomes have been extensively studied, the molecular mechanisms regulating cotton trichomes remain elusive. Recent findings have uncovered similarities between cotton fiber and stem trichomes development, suggesting that research on one type could inform the other (Yuan, Cao, et al., 2021).…”

“…Gossypium hirsutum and G. barbadense are the two major cultivated allotetraploid species used in cotton production, but they exhibit distinct morphological differences, including fiber and stem trichomes phenotypes (Yuan, Cao, et al., 2021). According to stem trichomes phenotypic data from the USDA National Cotton Germplasm Collection, over half of the 4323 G. barbadense varieties either lacked or had very few trichomes on their stems, while 97% of the 11 442 G. hirsutum varieties exhibited single or clustered trichomes on their stems; only 3% had glabrous stems (Yuan, Cao, et al., 2021). The hairless stem characteristic of G. barbadense was reported to be caused by a copia‐like retrotransposon insertion in a homeodomain‐leucine zipper gene ( HD1 ; Ding et al., 2015).…”