BBX32 integrates ethylene and light signaling to delay apical hook opening and optimize seedling soil emergence

New Phytologist, Год журнала: 2025, Номер unknown

Опубликована: Май 28, 2025

Summary In terrestrial plants, seeds often germinate and initiate early development in the darkness under layers of soil. Soil overlay promotes ethylene accumulation to maintain hook until seedlings reach soil surface. During this phase etiolated growth emergence, perceive changing light fluence. Coordinated interplay signaling pathways ensures optimal timing apical opening enhanced emergence. Here, we report that cooperatively act on B‐box protein BBX32 regulate enhance emergence . Ethylene induces expression dark. CONSTITUTIVE PHOTOMORPHOGENIC 1 degrades dark while enhances during de‐etiolation. bbx32 mutants exhibit accelerated opening, overexpressing lines show delayed opening. Genetic analyses reveal functions concert with PHYTOCHROME‐INTERACTING FACTOR 3 negatively HOOKLESS a PIF3‐dependent manner delay Under cover, 35S:BBX32 reduced seedling respectively. Our study illustrates role synchronizing ethylene‐mediated

Язык: Английский

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BBX32 dampens E3 ligase activity to promote greening in emerging seedlings

Journal of Integrative Plant Biology, Год журнала: 2025, Номер unknown

Опубликована: Май 30, 2025

ABSTRACT Germinating seeds undergo elaborate de‐etiolation developmental transitions upon initial soil emergence. As central transcription factors promoting cotyledon greening, the abundance of ETHYLENE‐INSENSITIVE 3 (EIN3) and PHYTOCHROME‐INTERACTING FACTOR (PIF3) are strictly controlled by physically associating themselves with EIN3‐BINDING F BOX PROTEINS 1 2 (EBF1/2) for ubiquitination. Here, we report that B‐box zinc‐finger protein BBX32, as a positive regulator during seedling de‐etiolation. BBX32 is robustly elevated dark‐to‐light transitions. Constitutively expressing ultimately protects against severe photobleaching damage synchronizing accumulation protochlorophyllide (Pchlide) differentiation etioplast–chloroplast apparatus in buried seedlings. Specifically, directly interacts EIN3, PIF3 EBF1/2. These associations disrupt assembly SCF EBF1/2 ‐EIN3/PIF3 E3 ligation complexes, thus dampening ligase activity controlling EIN3/PIF3 stability. Under conditions, BBX32‐ox largely rescues greening deficiency EBF1ox , all EIN3ox/bbx32 seedlings override bbx32 mutant defect successfully turn green. Both biochemical findings genetic evidence reveal novel regulatory paradigm which dampens binding to achieve green changes light or environmental conditions.

Язык: Английский

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ABSCISIC ACID INSENSITIVE 3 promotes auxin signalling by regulating SHY2 expression to control primary root growth in response to dehydration stress

Journal of Experimental Botany, Год журнала: 2024, Номер 75(16), С. 5111 - 5129

Опубликована: Май 20, 2024

Plants combat dehydration stress through different strategies including root architectural changes. Here we show that when exposed to varying levels of stress, primary growth in Arabidopsis is modulated by regulating meristem activity. Abscisic acid (ABA) concert with auxin signalling adjust according levels. ABSCISIC ACID INSENSITIVE 3 (ABI3), an ABA-responsive transcription factor, stands at the intersection ABA and fine-tunes response stress. Under low or induction ABI3 expression promotes decreasing SHY2, a negative regulator response. This further enhances transporter gene PIN1 cell cycle CYCB1;1, resulting increase size length. Higher repress promote 5 (ABI5) expression. elevates SHY2 expression, thereby impairing activity retarding growth. Notably, ABI5 can only absence ABI3. Such concentration-dependent therefore functions as regulatory sensor orchestrates coordinating its downstream regulation.

Язык: Английский

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Involvement of the tomato BBX16 and BBX17 microProteins in reproductive development

Plant Physiology and Biochemistry, Год журнала: 2024, Номер 213, С. 108873 - 108873

Опубликована: Июнь 21, 2024

BBXs are B-Box zinc finger proteins that can act as transcription factors and regulators of protein complexes. Several BBX play important roles in plant development. Two Arabidopsis thaliana microProteins belonging to the family, named miP1a miP1b, homotypically interact with modulate activity other proteins, including CONSTANS, which transcriptionally activates florigen, FLOWERING LOCUS T. plants overexpressing miP1b showed delayed flowering. In tomato, closest homologs SlBBX16 SlBBX17. This study was aimed at investigating whether constitutive expression SlBBX16/17 tomato impacted reproductive The heterologous two caused a delay flowering transition; however, effect weaker than observed when native miP1a/b were overexpressed. overexpression SlBBX17 prolonged period; this accompanied by downregulation inhibitors Self Pruning (SP) SP5G. hetero-oligomerize TCMP-2, cystine-knot peptide involved pattern regulation early fruit development tomato. increased both also alterations development: we case decrease number size ripe fruits compared WT plants, while for SlBBX16, production up breaker stage. These effects associated changes GA-responsive genes.

Язык: Английский

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Genome-Wide Identification, Characterization and Expression Patterns of the DBB Transcription Factor Family Genes in Wheat

International Journal of Molecular Sciences, Год журнала: 2024, Номер 25(21), С. 11654 - 11654

Опубликована: Окт. 30, 2024

Double B-box (DBB) proteins are plant-specific transcription factors (TFs) that play crucial roles in plant growth and stress responses. This study investigated the classification, structure, conserved motifs, chromosomal locations, cis-elements, duplication events, expression levels, protein interaction network of DBB TF family genes common wheat (

Язык: Английский

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The B-box protein BBX13/COL15 suppresses photoperiodic flowering by attenuating the action of CONSTANS in Arabidopsis

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2024, Номер unknown

Опубликована: Апрель 19, 2024

Summary The optimal timing of transition from vegetative to floral reproductive phase is critical for plant productivity and agricultural yields. Light plays a decisive role in regulating this transition. B-box (BBX) family transcription factors regulates several light-mediated developmental processes plants, including flowering. Here, we identify previously uncharacterized group II member the BBX family, BBX13/COL15, as negative regulator flowering under long-day conditions. BBX13 primarily expressed leaf vasculature, buds, flowers. Its spatial expression pattern similar major time regulators CO FT. bbx13 mutants flower early, while -overexpressors exhibit delayed long days. Genetic analyses showed that acts upstream FT pathway negatively their expression. We found physically interacts with inhibits CO-mediated transcriptional activation . In addition, directly binds CORE2 motif on promoter, site where also binds. Furthermore, our ChIP data indicates reduces vivo binding promoter. Through luciferase assay, All these together suggest BBX13/COL15 represses Arabidopsis by attenuating activity. statement BBX13, protein B-Box factors, thaliana genetically

Язык: Английский

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Overexpression of tomatoSlBBX16andSlBBX17impacts fruit development and gibberellin metabolism

bioRxiv (Cold Spring Harbor Laboratory), Год журнала: 2023, Номер unknown

Опубликована: Авг. 13, 2023

Abstract BBXs are B-Box zinc finger proteins that can act as transcription factors and regulators of protein complexes. Several BBX play important roles in plant development. Two Arabidopsis thaliana microProteins belonging to the family, named miP1a miP1b, homotypically interact with modulate activity other proteins, including CONSTANS, which transcriptionally activates florigen, FLOWERING LOCUS T . In tomato, closest homologs miP1b Sl BBX16 BBX17. To deepen our understanding role tomato flowering, we constitutively expressed BBX16/17 examined possible interacting partners. Overexpression two caused a delay flowering transition; however, effect was weaker than observed plants overexpressing native miP1a/b. overexpression SlBBX17 prolonged period; this accompanied by downregulation inhibitors Self Pruning ( SP ) SP5G BBX17 able hetero-oligomerize TCMP-2, cystine-knot peptide involved pattern fruit development tomato. Increasing expression both also alterations development: resulted diminished number size ripe fruits compared WT plants, while SlBBX16 delayed production up breaker stage. These effects were associated changes genes regulating gibberellin content.

Язык: Английский

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