The Arabidopsis mutant, fy-1, has an ABA-insensitive germination phenotype

Seed germination and flowering initiation are both transitions responding to similar seasonal cues. This study shows that ABSCISIC ACID-INSENSITIVE MUTANT 5 (ABI5), a bZIP transcription factor, which plays an important role in the abscisic acid (ABA)-arrested seed germination, is robustly associated with the floral transition in Arabidopsis. Under long-day conditions, overexpression of ABI5 could delay floral transition through upregulating FLOWERING LOCUS C (FLC) expression. In contrast, ectopically overexpressing FLC in an abi5 mutant reversed the earlier flowering phenotype. Further analysis indicated that transactivation of FLC could be promoted by ABI5 and/or other abscisic acid-responsive element (ABRE)-binding factors (ABFs). The expression of FLC that was promoted by ABI5 and/or other ABFs could be blocked in a triple SNF1-related protein kinase (SnRK) mutant, snrk2.2/2.3/2.6, despite the presence of ABA. In sharp contrast, when SnRK2.6 was coexpressed, the reduction of transactivity of FLC was reverted in mesophyll protoplasts of snrk2.2/2.3/2.6. Additional results from analysing transgenic plants carrying mutations of phosphoamino acids (ABI5 S42AS145AT201A), which are conserved in ABI5, suggested that SnRK2-mediated ABI5 and/or ABF phosphorylation may be crucial for promoting FLC expression. The transgenic plants ABI5 S42AS145AT201A were insensitive to ABA in seed germination, in addition to having an earlier flowering phenotype. Direct binding of ABI5 to the ABRE/G-box promoter elements existing in FLC was demonstrated by chromatin immunoprecipitation. Mutations at the ABRE/G-box regions in FLC promoter sequences abolished the ABI5-promoted transactivation of FLC. In summary, these results may decipher the inhibitory effect of ABA on floral transition in Arabidopsis.

show abstract

“…3 and Supplementary Fig. S2; Jiang et al ., 2012). ABI5 and/or other ABFs could distinctly promote the expression of FLC (Figs.…”

Section: Discussionmentioning

confidence: 99%

The inhibitory effect of ABA on floral transition is mediated by ABI5 in Arabidopsis

Wang

Lin

et al. 2013

Journal of Experimental Botany

232

198

View full text Add to dashboard Cite

show abstract

“…2), and SnRK2.3 (Finkelstein and Somerville, 1990;Söderman et al, 2000;Carles et al, 2002;Fujii et al, 2007;Tran et al, 2007;Moes et al, 2008;Li et al, 2011;Jiang et al, 2012;Du et al, 2013;Kim et al, 2013), in the wild type, myb96-ox, and myb96-1, in the absence of ABA. In seeds, many genes were differentially expressed in myb96-ox and myb96-1, but MYB96 regulation of ABI4 was most likely relevant (Fig.…”

Section: Abi4 Is Up-regulated In Myb96-oxmentioning

confidence: 99%

The Arabidopsis MYB96 Transcription Factor Is a Positive Regulator of ABSCISIC ACID-INSENSITIVE4 in the Control of Seed Germination

Lee

Yoon

et al. 2015

Plant Physiol.

View full text Add to dashboard Cite

Seed germination is a key developmental transition that initiates the plant life cycle. The timing of germination is determined by the coordinated action of two phytohormones, gibberellin and abscisic acid (ABA). In particular, ABA plays a key role in integrating environmental information and inhibiting the germination process. The utilization of embryonic lipid reserves contributes to seed germination by acting as an energy source, and ABA suppresses lipid degradation to modulate the germination process. Here, we report that the ABA-responsive R2R3-type MYB transcription factor MYB96, which is highly expressed in embryo, regulates seed germination by controlling the expression of ABSCISIC ACID-INSENSITIVE4 (ABI4) in Arabidopsis (Arabidopsis thaliana). In the presence of ABA, germination was accelerated in MYB96-deficient myb96-1 seeds, whereas the process was significantly delayed in MYB96-overexpressing activation-tagging myb96-ox seeds. Consistently, myb96-1 seeds degraded a larger extent of lipid reserves even in the presence of ABA, while reduced lipid mobilization was observed in myb96-ox seeds. MYB96 directly regulates ABI4, which acts as a repressor of lipid breakdown, to define its spatial and temporal expression. Genetic analysis further demonstrated that ABI4 is epistatic to MYB96 in the control of seed germination. Taken together, the MYB96-ABI4 module regulates lipid mobilization specifically in the embryo to ensure proper seed germination under suboptimal conditions.

show abstract

“…FY is the Arabidopsis homolog of the yeast RNA 39 processing factor Pfs2p (Simpson et al, 2003). A previous study demonstrated that the fy-1 mutant in Landsberg erecta background has weak seed dormancy (Jiang et al, 2012). To check if the function of FY in seed dormancy control is independent of genetic background, we Figure 1.…”

Section: Mutants Of Rna 39 Processing Factors Display Weak Seed Dormamentioning

confidence: 99%

Seed Dormancy in Arabidopsis Is Controlled by Alternative Polyadenylation of DOG1

et al. 2015

View full text Add to dashboard Cite

ORCID IDs: 0000-0001-7449-8081 (M.C.); 0000-0001-8764-6370 (F.L.).DOG1 (Delay of Germination 1) is a key regulator of seed dormancy in Arabidopsis (Arabidopsis thaliana) and other plants. Interestingly, the C terminus of DOG1 is either absent or not conserved in many plant species. Here, we show that in Arabidopsis, DOG1 transcript is subject to alternative polyadenylation. In line with this, mutants in RNA 39 processing complex display weakened seed dormancy in parallel with defects in DOG1 proximal polyadenylation site selection, suggesting that the short DOG1 transcript is functional. This is corroborated by the finding that the proximally polyadenylated short DOG1 mRNA is translated in vivo and complements the dog1 mutant. In summary, our findings indicate that the short DOG1 protein isoform produced from the proximally polyadenylated DOG1 mRNA is a key player in the establishment of seed dormancy in Arabidopsis and characterizes a set of mutants in RNA 39 processing complex required for production of proximally polyadenylated functional DOG1 transcript.

show abstract

The Arabidopsis mutant, fy-1, has an ABA-insensitive germination phenotype

Cited by 34 publications

References 35 publications

The inhibitory effect of ABA on floral transition is mediated by ABI5 in Arabidopsis

The inhibitory effect of ABA on floral transition is mediated by ABI5 in Arabidopsis

The Arabidopsis MYB96 Transcription Factor Is a Positive Regulator of ABSCISIC ACID-INSENSITIVE4 in the Control of Seed Germination

Seed Dormancy in Arabidopsis Is Controlled by Alternative Polyadenylation of DOG1

Contact Info

Product

Resources

About