Functional symmetry of the B3 network controlling seed development

Suzuki, Masaharu; McCarty, Donald R.

doi:10.1016/j.pbi.2008.06.015

Cited by 165 publications

(147 citation statements)

References 53 publications

Supporting

Mentioning

145

Contrasting

Unclassified

Order By: Relevance

“…The VAL1/HSI2, VAL2/HSL1, and VAL3 genes also encode B3 domain proteins that act to promote the transition from embryo to seedling development by shutting down the AFL network prior to germination (Suzuki et al, 2007;Suzuki and McCarty, 2008;Veerappan et al, 2012). In the val1 val2 double mutant, somatic embryos form on the seedlings, in part because the AFL genes are not properly repressed.…”

Section: Fus3 Embryo Transcription Factors and The Afl/ Val Networkmentioning

confidence: 99%

See 1 more Smart Citation

Identification of Direct Targets of FUSCA3, a Key Regulator of Arabidopsis Seed Development

2013

View full text Add to dashboard Cite

FUSCA3 (FUS3) is a B3 domain transcription factor that is a member of the LEAFY COTYLEDON (LEC) group of genes. The LEC genes encode proteins that also include LEC2, a B3 domain factor related to FUS3, and LEC1, a CCAAT box-binding factor. LEC1, LEC2, and FUS3 are essential for plant embryo development. All three loss-of-function mutants in Arabidopsis (Arabidopsis thaliana) prematurely exit embryogenesis and enter seedling developmental programs. When ectopically expressed, these genes promote embryo programs in seedlings. We report on chromatin immunoprecipitation-tiling array experiments to globally map binding sites for FUS3 that, along with other published work to assess transcriptomes in response to FUS3, allow us to determine direct from indirect targets. Many transcription factors associated with embryogenesis are direct targets of FUS3, as are genes involved in the seed maturation program. FUS3 regulates genes encoding microRNAs that, in turn, control transcripts encoding transcription factors involved in developmental phase changes. Examination of direct targets of FUS3 reveals that FUS3 acts primarily or exclusively as a transcriptional activator. Regulation of microRNA-encoding genes is one mechanism by which FUS3 may repress indirect target genes. FUS3 also directly up-regulates VP1/ABI3-LIKE1 (VAL1), encoding a B3 domain protein that functions as a repressor of transcription. VAL1, along with VAL2 and VAL3, is involved in the transition from embryo to seedling development. Many genes are responsive to FUS3 and to VAL1/VAL2 but with opposite regulatory consequences. The emerging picture is one of complex cross talk and interactions among embryo transcription factors and their target genes.

show abstract

Section: Fus3 Embryo Transcription Factors and The Afl/ Val Networkmentioning

confidence: 99%

“…7). However, it remains to be determined if the VAL proteins associate with RY motifs via the B3 domain (Suzuki and McCarty, 2008).…”

Section: Fus3 Embryo Transcription Factors and The Afl/ Val Networkmentioning

confidence: 99%

Identification of Direct Targets of FUSCA3, a Key Regulator of Arabidopsis Seed Development

2013

View full text Add to dashboard Cite

show abstract

“…We hypothesized that if lack of ABI3 function results in the embryo stay-green phenotype, then the expression of downstream ABI3 targets will be affected and the factors responsible for embryo-degreening should represent a subset of the targets regulated by ABA. To examine this, we performed microarray analyses to identify the transcriptome profile of embryos in their late maturation phase (13 DAF) when embryos begin to enter the degreening phase (13)(14)(15)(16) and when ABI3 expression is maximal (SI Appendix, Fig. S1C).…”

Section: Abi3-6mentioning

confidence: 99%

ABI3 controls embryo degreening through Mendel'sIlocus

Delmas

Sankaranarayanan

Deb

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

141

151

View full text Add to dashboard Cite

Chlorophyll (chl) is essential for light capture and is the starting point that provides the energy for photosynthesis and thus plant growth. Obviously, for this reason, retention of the green chlorophyll pigment is considered a desirable crop trait. However, the presence of chlorophyll in mature seeds can be an undesirable trait that can affect seed maturation, seed oil quality, and meal quality. Occurrence of mature green seeds in oil crops such as canola and soybean due to unfavorable weather conditions during seed maturity is known to cause severe losses in revenue. One recently identified candidate that controls the chlorophyll degradation machinery is the stay-green gene, SGR1 that was mapped to Mendel's I locus responsible for cotyledon color (yellow versus green) in peas. A defect in SGR1 leads to leaf stay-green phenotypes in Arabidopsis and rice, but the role of SGR1 in seed degreening and the signaling machinery that converges on SGR1 have remained elusive. To decipher the gene regulatory network that controls degreening in Arabidopsis, we have used an embryo staygreen mutant to demonstrate that embryo degreening is achieved by the SGR family and that this whole process is regulated by the phytohormone abscisic acid (ABA) through ABSCISIC ACID INSEN-SITIVE 3 (ABI3); a B3 domain transcription factor that has a highly conserved and essential role in seed maturation, conferring desiccation tolerance. Misexpression of ABI3 was sufficient to rescue cold-induced green seed phenotype in Arabidopsis. This finding reveals a mechanistic role for ABI3 during seed degreening and thus targeting of this pathway could provide a solution to the green seed problem in various oil-seed crops.freezing tolerance | nondormant T he success of angiosperms impinges on their ability to desiccate and protect their embryos in a dormant state until favorable conditions are perceived. In many angiosperms and oilseed plants such as Arabidopsis and canola, this desiccation process during seed maturation is intricately coupled to loss of chlorophyll (chl) from photosynthetically active embryos (1). During the embryo maturation phase, as the embryos begin to lose their chlorophyll, they concomitantly initiate the process of acquisition of desiccation tolerance and dormancy, thereby producing mature, brown (degreened) and dormant seeds. The persistence of chlorophyll in mature seeds has negative impacts on seed storability in many commercial plant species such as canola, cabbage, carrot, geranium, and soybean (2-4). Apart from contributing to reduced storability, prevalence of green seeds in mature oil seeds (canola and soybean) is also associated with reduced shelf life of oil and production of unfavorable odors and flavors. Particularly, in canola, which is one of the major global cash crops, the frost-induced green seed problem has been estimated to result in an annual loss of $150 million in revenue in North America alone (5, 6).During seed development, abscisic acid (ABA) is known to control mid to late stages of embryo maturation...

show abstract

“…These processes are orchestrated by the LEAFY COTY-LEDON (LEC) transcription factors (LEC1, LEC2, and FUSCA3 in Arabidopsis) and mediated by the growth hormones auxin and gibberellin (GA), the stress hormone abscisic acid (ABA), and the seed-specific, ABA-activated transcription factor ABSCISIC ACID INSENSITIVE3 (ABI3) (Holdsworth et al, 1999;Gutierrez et al, 2007;Braybrook and Harada, 2008;Suzuki and McCarty, 2008). ABI3 activates the previously mentioned transcription factor HSFA9 (Kotak et al, 2007).…”

mentioning

confidence: 99%

ARABIDOPSIS THALIANA HOMEOBOX25 Uncovers a Role for Gibberellins in Seed Longevity

et al. 2013

View full text Add to dashboard Cite

Seed longevity is crucial for agriculture and plant genetic diversity, but it is limited by cellular damage during storage. Seeds are protected against aging by cellular defenses and by structures such as the seed coat. We have screened an activation-tagging mutant collection of Arabidopsis (Arabidopsis thaliana) and selected four dominant mutants with improved seed longevity (isl1-1D to isl4-1D) under both natural and accelerated aging conditions. In the isl1-1D mutant, characterized in this work, overexpression of the transcription factor ARABIDOPSIS THALIANA HOMEOBOX25 (ATHB25; At5g65410) increases the expression of GIBBERELLIC ACID3-OXIDASE2, encoding a gibberellin (GA) biosynthetic enzyme, and the levels of GA 1 and GA 4 are higher (3.2-and 1.4-fold, respectively) in the mutant than in the wild type. The morphological and seed longevity phenotypes of the athb25-1D mutant were recapitulated in transgenic plants with moderate (4-to 6-fold) overexpression of ATHB25. Simultaneous knockdown of ATHB25, ATHB22, and ATHB31 expression decreases seed longevity, as does loss of ATHB25 and ATHB22 function in a double mutant line. Seeds from wild-type plants treated with GA and from a quintuple DELLA mutant (with constitutive GA signaling) are more tolerant to aging, providing additional evidence for a role of GA in seed longevity. A correlation was observed in several genotypes between seed longevity and mucilage formation at the seed surface, suggesting that GA may act by reinforcing the seed coat. This mechanism was supported by the observation of a maternal effect in reciprocal crosses between the wild type and the athb25-1D mutant.

show abstract

Functional symmetry of the B3 network controlling seed development

Cited by 165 publications

References 53 publications

Identification of Direct Targets of FUSCA3, a Key Regulator of Arabidopsis Seed Development

Identification of Direct Targets of FUSCA3, a Key Regulator of Arabidopsis Seed Development

ABI3 controls embryo degreening through Mendel'sIlocus

ARABIDOPSIS THALIANA HOMEOBOX25 Uncovers a Role for Gibberellins in Seed Longevity

Contact Info

Product

Resources

About