GLABROUS INFLORESCENCE STEMS3 (GIS3) regulates trichome initiation and development in Arabidopsis

Abstract

SummaryArabidopsis trichome formation is an excellent model for studying various aspects of plant cell development and cell differentiation. Our previous works have demonstrated that several C2H2 zinc finger proteins, including GIS, GIS2, ZFP5, ZFP6 and ZFP8, control trichome cell development through GA and cytokinin signalling in Arabidopsis.We identified a novel C2H2 zinc finger protein, GLABROUS INFLORESCENCE STEMS 3 (GIS3), which is a key factor in regulating trichome development in Arabidopsis.In comparison with wild-type plants, loss-of-function of GIS3 mutants exhibited a significantly decreased number of trichomes in cauline leaves, lateral branches, sepals of flowers, and main stems. Overexpression of GIS3 resulted in increased trichome densities in sepal, cauline leaves, lateral branches, main inflorescence stems and in the appearance of ectopic trichomes on carpels.The molecular and genetic analyses show that GIS3 acts upstream of GIS, GIS2, ZFP8 and the key trichome initiation factors, GL1 and GL3. Steroid-inducible gene expression analyses and chromatin immunoprecipitation (ChIP) experiments suggest that GIS and GIS2 are the direct target genes of GIS3.

NTL8 Regulates Trichome Formation in Arabidopsis by Directly Activating R3 MYB Genes TRY and TCL1

“…So far, all the other identified trichome formationregulating transcription factors, including the C2H2 transcription factors GIS, GIS2, and GIS3, the ZINC FINGER transcription factors ZFP5, ZFP6, and ZFP8, and the miR156-directed transcription factor SPL9, are reported to function through the regulation of, directly or indirectly, the expression of the key transcription factor genes in the trichome formation pathway (Gan et al, 2006(Gan et al, , 2007Yu et al, 2010;Zhou et al, 2011Zhou et al, , 2013Sun et al, 2015). Our experimental data suggest that this is also the case with NTL8.…”

“…Data represent the mean 6 SD of 18 plants. Yu et al, 2010;Zhou et al, 2011Zhou et al, , 2013Sun et al, 2015). To examine if this is the case for NTL8, we tested, by using qRT-PCR, the expression of the MBW complex component genes TTG1, GL1, GL3, and EGL3, and their target genes GL2 and singlerepeat R3 MYB genes TRY, CPC, ETC1, ETC2, ETC3, TCL1, and TCL2 in the ntl8-1D mutant seedlings.…”

“…The C2H2 transcription factors GLABROUS INFLORES-CENCE STEMS (GIS), GIS2, and GIS3, the ZINC FINGER transcription factors ZINC FINGER PROTEIN5 (ZFP5), ZFP6, and ZFP8, and the plant-specific transcription factor SQUAMOSA PROMOTER BINDING PROTEIN LIKE9 (SPL9) have been identified as regulators of trichome formation (Gan et al, 2006(Gan et al, , 2007Yu et al, 2010;Zhou et al, 2011Zhou et al, , 2013Sun et al, 2015). Most of these transcription factors regulate trichome formation via regulating, directly or indirectly, the expression of the key transcription factor genes.…”

“…Most of these transcription factors regulate trichome formation via regulating, directly or indirectly, the expression of the key transcription factor genes. For example, GIS, GIS3, ZFP5, and ZFP8 can regulate the expression of the MBW complex component genes (Gan et al, 2006(Gan et al, , 2007Zhou et al, 2011Zhou et al, , 2013Sun et al, 2015), whereas SPL9 can directly regulate the expression of the R3 MYB transcription factor genes TRY and TCL1 (Yu et al, 2010).…”

MYB and HD-ZIP IV homologs related to trichome formation are involved in epidermal bladder cell development in the halophyteMesembryanthemum crystallinumL.

“…The relative expression of the transcript levels of trichome-related genes was calculated by △CT method (Livak & Schmittgen, 2001) after being normalized to the internal control of gene encoding actin (ACTIN2). The primers for the genes were designed according to Tominaga-Wada et al (2013) and Sun et al (2015) which were shown in Supplemental Table 2.…”