Phytohormonal Networks Promote Differentiation of Fiber Initials on Pre-Anthesis Cotton Ovules Grown In Vitro and In Planta

Abstract

The number of cotton (Gossypium sp.) ovule epidermal cells differentiating into fiber initials is an important factor affecting cotton yield and fiber quality. Despite extensive efforts in determining the molecular mechanisms regulating fiber initial differentiation, only a few genes responsible for fiber initial differentiation have been discovered. To identify putative genes directly involved in the fiber initiation process, we used a cotton ovule culture technique that controls the timing of fiber initial differentiation by exogenous phytohormone application in combination with comparative expression analyses between wild type and three fiberless mutants. The addition of exogenous auxin and gibberellins to pre-anthesis wild type ovules that did not have visible fiber initials increased the expression of genes affecting auxin, ethylene, ABA and jasmonic acid signaling pathways within 1 h after treatment. Most transcripts expressed differentially by the phytohormone treatment in vitro were also differentially expressed in the ovules of wild type and fiberless mutants that were grown in planta. In addition to MYB25-like, a gene that was previously shown to be associated with the differentiation of fiber initials, several other differentially expressed genes, including auxin/indole-3-acetic acid (AUX/IAA) involved in auxin signaling, ACC oxidase involved in ethylene biosynthesis, and abscisic acid (ABA) 8'-hydroxylase an enzyme that controls the rate of ABA catabolism, were co-regulated in the pre-anthesis ovules of both wild type and fiberless mutants. These results support the hypothesis that phytohormonal signaling networks regulate the temporal expression of genes responsible for differentiation of cotton fiber initials in vitro and in planta.

Comparative fiber property and transcriptome analyses reveal key genes potentially related to high fiber strength in cotton (Gossypium hirsutum L.) line MD52ne

“…Five expansins (Gh_D13G0786, Gh_A11G2917, Gh_A04G0707, Gh_A12G1619, and Gh_A12G1619), three PME s (Gh_A05G1180, Gh_D06G0865, and Gh_D07G0145), and five XET s (Gh_A03G1432, Gh_D02G1891, Gh_D05G0764, Gh_A11G0768, and Gh_D13G0290) were highly expressed in MD52ne fibers (Table 5 ). Four Sus (Gh_A07G0665, Gh_A08G1031, Gh_D08G1309, and Gh_D11G0438) and multiple lipid transfer proteins involved in fiber development [ 29 , 40 , 41 ] were co-expressed at actively elongating MD52ne fibers.…”

“…6 ). In addition, transcripts ( AUX/IAA , auxin-responsive GH3 protein , and GAST1 ) involved in auxin and GA were required for differentiating and elongating fibers [ 41 , 55 ]. For promoting fiber elongation, multiple expansins involved in loosening the cell walls and lipid transfer proteins involved in fiber elongating [ 29 ] were also up-regulated in the MD52ne fibers (Table 5 and Fig.…”

DNA Methylation and the Potential Role of Methyl‐Containing Nutrients in Cardiovascular Diseases

“…Although CpG islands have been identified as being located in both intragenic and intergenic areas, further study is required to ascertain the functioning of each of these domains. The methylation of DNA at sites inside a promoter region or other sites purposed with regulation is frequently linked with the “silencing” of gene expression, and silencing has a similar capacity to arise when DNA methylation is modified external to a promoter area and not internal to a CpG island [ 22 , 23 ]. Often referred to as a “CpG island shore,” this occurs in sequences approximately 2 kb upstream [ 10 , 21 ].…”

Flavonoids and Antimicrobial Properties of Begonia fischeri var. palustris in vitro Plantlets

“…This reduction was previously shown in experiments with intact plants in kindergartens and libraries (Fershalova et al, 2018). One of the further directions of the investigation should be the nutritious medium optimization to get a significant increase of exudative flavonoids amounts for high antimicrobial activity (Kim et al, 2015).…”