Global Analysis of DELLA Direct Targets in Early Gibberellin Signaling in<i>Arabidopsis</i>

Zentella, Rodolfo; Zhang, Zhonglin; Park, Me‐Hea; Thomas, Stephen G.; Endo, Akira; Murase, Kohji; Fleet, Christine M.; Jikumaru, Yusuke; Nambara, Eiji; Kamiya, Yûji; Sun, Tai-ping

doi:10.1105/tpc.107.054999

Cited by 563 publications

(645 citation statements)

References 127 publications

Supporting

Mentioning

602

Contrasting

Unclassified

Order By: Relevance

“…Consistent with a previous study, our qRT-PCR analysis demonstrated that the expression of GhGID1-a/GhGID1-b was strongly suppressed in cotton leaves after GA treatment (Supplemental Fig. S7C), similar to AtGID1a and AtGID1b in Arabidopsis (Zentella et al, 2007). In addition, the transcript levels of GhGID1-a and GhGID1-b were also significantly inhibited via the overexpression of GbWRKY1 (Fig.…”

Section: Gbwrky1 Negatively Regulates the Ja Signaling Pathwaysupporting

confidence: 91%

“…GA is known to promote GA signaling transduction by destabilizing a number of GA repressors, the DELLA proteins (GIBBERELLIC ACID INSENSITIVE, REPRESSOR OF GIBBERELLIC ACID INSENSITIVE3 [RGA], RGA-LIKE1 [RGL1], RGL2, and RGL3), in Arabidopsis (Harberd et al, 2009 Zentella et al, 2007), which are downregulated in quadruple-DELLA mutant plants (Josse et al, 2011). To determine whether the GA signaling pathway is influenced by GbWRKY1, the transcripts of these putative DELLA targets (GID1a, GID1b, XERICO, SCL3, bHLH137, LBD40, and MYB) were detected in Arabidopsis through quantitative PCR.…”

Section: Gbwrky1 Negatively Regulates the Ja Signaling Pathwaymentioning

confidence: 99%

See 1 more Smart Citation

Cotton WRKY1 Mediates the Plant Defense-to-Development Transition during Infection of Cotton by Verticillium dahliae by Activating JASMONATE ZIM-DOMAIN1 Expression

Luo

et al. 2014

Plant Physiology

129

View full text Add to dashboard Cite

Plants have evolved an elaborate signaling network to ensure an appropriate level of immune response to meet the differing demands of developmental processes. Previous research has demonstrated that DELLA proteins physically interact with JASMONATE ZIM-DOMAIN1 (JAZ1) and dynamically regulate the interaction of the gibberellin (GA) and jasmonate (JA) signaling pathways. However, whether and how the JAZ1-DELLA regulatory node is regulated at the transcriptional level in plants under normal growth conditions or during pathogen infection is not known. Here, we demonstrate multiple functions of cotton (Gossypium barbadense) GbWRKY1 in the plant defense response and during development. Although GbWRKY1 expression is induced rapidly by methyl jasmonate and infection by Verticillium dahliae, our results show that GbWRKY1 is a negative regulator of the JA-mediated defense response and plant resistance to the pathogens Botrytis cinerea and V. dahliae. Under normal growth conditions, GbWRKY1-overexpressing lines displayed GA-associated phenotypes, including organ elongation and early flowering, coupled with the down-regulation of the putative targets of DELLA. We show that the GA-related phenotypes of GbWRKY1-overexpressing plants depend on the constitutive expression of Gossypium hirsutum GhJAZ1. We also show that GhJAZ1 can be transactivated by GbWRKY1 through TGAC core sequences, and the adjacent sequences of this binding site are essential for binding specificity and affinity to GbWRKY1, as revealed by dual-luciferase reporter assays and electrophoretic mobility shift assays. In summary, our data suggest that GbWRKY1 is a critical regulator mediating the plant defense-to-development transition during V. dahliae infection by activating JAZ1 expression.

show abstract

Section: Gbwrky1 Negatively Regulates the Ja Signaling Pathwaysupporting

confidence: 91%

Section: Gbwrky1 Negatively Regulates the Ja Signaling Pathwaymentioning

confidence: 99%

Cotton WRKY1 Mediates the Plant Defense-to-Development Transition during Infection of Cotton by Verticillium dahliae by Activating JASMONATE ZIM-DOMAIN1 Expression

Luo

et al. 2014

Plant Physiology

129

View full text Add to dashboard Cite

show abstract

“…When both DELLA genes were null (la cry-s), there was a strong reduction in expression of the biosynthesis genes PsGA20ox1, PsGA3ox1, and PsGA3ox2, and a strong promotion of the deactivation genes PsGA2ox1 and PsGA2ox2, compared with LA cry-s or la CRYplants. Therefore, DELLA proteins promote the expression of GA synthesis genes and inhibit that of GA deactivation genes, indicating that in roots, DELLAs are an integral part of the feedback and feed-forward phenomena, whereby bioactive GA reduces GA synthesis and speeds up GA deactivation Zentella et al, 2007).…”

Section: Discussionmentioning

confidence: 99%

“…For example, in the Arabidopsis (Arabidopsis thaliana) DELLA mutant rga, the expression of the biosynthesis gene GA4 is reduced, indicating that high DELLA protein levels are associated with an up-regulation of GA synthesis genes (Silverstone et al, 2001). More recently Zentella et al (2007) provided evidence that the Arabidopsis GA synthesis genes GA3ox1 (GA4) and GA20ox2 are direct DELLA targets.…”

mentioning

confidence: 99%

The Pea DELLA Proteins LA and CRY Are Important Regulators of Gibberellin Synthesis and Root Growth

et al. 2008

View full text Add to dashboard Cite

The theory that bioactive gibberellins (GAs) act as inhibitors of inhibitors of plant growth was based originally on the slender pea (Pisum sativum) mutant (genotype la cry-s), but the molecular nature of this mutant has remained obscure. Here we show that the genes LA and CRY encode DELLA proteins, previously characterized in other species (Arabidopsis [Arabidopsis thaliana] and several grasses) as repressors of growth, which are destabilized by GAs. Mutations la and cry-s encode nonfunctional proteins, accounting for the fact that la cry-s plants are extremely elongated, or slender. We use the la and cry-s mutations to show that in roots, DELLA proteins effectively promote the expression of GA synthesis genes, as well as inhibit elongation. We show also that one of the DELLAregulated genes is a second member of the pea GA 3-oxidase family, and that this gene appears to play a major role in pea roots.It is well known that primary root growth is strongly influenced by the plant hormone GA (Davies, 2004). For example, the application of bioactive GA to roots treated with the growth inhibitor ancymidol completely restored growth to that of the untreated plants (Tanimoto, 1991). Yaxley et al. (2001) established the importance of GAs for root growth in peas (Pisum sativum) by using a variety of GA-deficient mutant plants. In the na-1 mutant, for example, root GA 1 levels, and root elongation, were significantly reduced compared with wild-type plants, and when the GA 1 content was restored to wild-type levels, so too was root elongation.The GAs act by destabilizing the growth inhibitory DELLA proteins (Peng et al., 1997;Harberd et al., 1998;Silverstone et al., 2001;Alvey and Harberd, 2005). In other words, GA acts as an ''inhibitor of an inhibitor '' (Harberd et al., 1998). Interestingly, there is also evidence that DELLA proteins promote the biosynthesis of active GAs. For example, in the Arabidopsis (Arabidopsis thaliana) DELLA mutant rga, the expression of the biosynthesis gene GA4 is reduced, indicating that high DELLA protein levels are associated with an up-regulation of GA synthesis genes (Silverstone et al., 2001 (Silverstone et al., 1998;Gubler et al., 2002). However, the available evidence indicates greater redundancy in dicots compared with monocots (Ikeda et al., 2001;Thomas and Hedden, 2006). There have been five DELLA genes isolated from Arabidopsis (GAI, RGA, RGL1, RGL2, and RGL3), yet only one in rice (SLR1), barley (SLN1), and maize (Zea mays; D8; Peng et al., 1997Peng et al., , 1999Silverstone et al., 1998;Ikeda et al., 2001;Chandler et al., 2002;Gubler et al., 2002), with the possibility of another DELLA gene in maize (D9; accession no. ABI84225). It should be noted, however, that DELLAs have been studied in fewer dicot model species than in monocot species. To date, DELLA-encoding genes from pea have not been reported, even though observations on the slender phenotype of pea triggered the early suggestion that GA acts an inhibitor of an inhibitor (Brian, 1957). The elongated slender phenotype, con...

show abstract

“…Seo et al (2006) indicated that endogenous ABA suppresses GA biosynthesis in developing seeds and in far-red light-treated mature seeds during imbibition through suppression of GA20ox and GA3ox genes in Arabidopsis. Zentella et al (2007) showed that the transcript levels of GA20ox1 in Arabidopsis plants are significantly reduced by exogenous ABA.…”

mentioning

confidence: 99%

High Temperature-Induced Abscisic Acid Biosynthesis and Its Role in the Inhibition of Gibberellin Action in Arabidopsis Seeds

et al. 2008

Self Cite

View full text Add to dashboard Cite

Suppression of seed germination at supraoptimal high temperature (thermoinhibiton) during summer is crucial for Arabidopsis (Arabidopsis thaliana) to establish vegetative and reproductive growth in appropriate seasons. Abscisic acid (ABA) and gibberellins (GAs) are well known to be involved in germination control, but it remains unknown how these hormone actions (metabolism and responsiveness) are altered at high temperature. Here, we show that ABA levels in imbibed seeds are elevated at high temperature and that this increase is correlated with up-regulation of the zeaxanthin epoxidase gene ABA1/ZEP and three 9-cis-epoxycarotenoid dioxygenase genes, NCED2, NCED5, and NCED9. Reverse-genetic studies show that NCED9 plays a major and NCED5 and NCED2 play relatively minor roles in high temperature-induced ABA synthesis and germination inhibition. We also show that bioactive GAs stay at low levels at high temperature, presumably through suppression of GA 20-oxidase genes, GA20ox1, GA20ox2, and GA20ox3, and GA 3-oxidase genes, GA3ox1 and GA3ox2. Thermoinhibition-tolerant germination of loss-of-function mutants of GA negative regulators, SPINDLY (SPY) and RGL2, suggests that repression of GA signaling is required for thermoinibition. Interestingly, ABA-deficient aba2-2 mutant seeds show significant expression of GA synthesis genes and repression of SPY expression even at high temperature. In addition, the thermoinhibition-resistant germination phenotype of aba2-1 seeds is suppressed by a GA biosynthesis inhibitor, paclobutrazol. We conclude that high temperature stimulates ABA synthesis and represses GA synthesis and signaling through the action of ABA in Arabidopsis seeds.

show abstract

Global Analysis of DELLA Direct Targets in Early Gibberellin Signaling inArabidopsis

Cited by 563 publications

References 127 publications

Cotton WRKY1 Mediates the Plant Defense-to-Development Transition during Infection of Cotton by Verticillium dahliae by Activating JASMONATE ZIM-DOMAIN1 Expression

Cotton WRKY1 Mediates the Plant Defense-to-Development Transition during Infection of Cotton by Verticillium dahliae by Activating JASMONATE ZIM-DOMAIN1 Expression

The Pea DELLA Proteins LA and CRY Are Important Regulators of Gibberellin Synthesis and Root Growth

High Temperature-Induced Abscisic Acid Biosynthesis and Its Role in the Inhibition of Gibberellin Action in Arabidopsis Seeds

Contact Info

Product

Resources

About