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

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. The B-box (BBX) family of transcription factors regulates several light-mediated developmental processes in plants, including flowering.

Light and abscisic acid interplay in early seedling development.

Abscisic acid (ABA) plays a crucial role in plant development, regulating germination, seedling development and stomatal movements, especially under adverse conditions. Light interacts with the ABA signalling pathway to fine tune these processes. Here, we provide an overview of the recent investigations on ABA-light interplay during early plant development after germination.

HY5 Suppresses, Rather Than Promotes, Abscisic Acid-Mediated Inhibition of Postgermination Seedling Development.

In contradiction with what has been reported before, the light signaling factor HY5 negatively regulates ABA-mediated inhibition of post-germination seedling growth by acting downstream to COP1.

CONSTITUTIVELY PHOTOMORPHOGENIC1 promotes ABA-mediated inhibition of post-germination seedling establishment.

Under acute stress conditions, precocious seedling development may result in the premature death of young seedlings, before they switch to autotrophic growth. The phytohormone abscisic acid (ABA) inhibits seed germination and post-germination seedling establishment under unfavorable conditions. Various environmental signals interact with the ABA pathway to optimize these early developmental events under stress.

Light signaling and UV-B-mediated plant growth regulation.

Light plays an important role in plants' growth and development throughout their life cycle. Plants alter their morphological features in response to light cues of varying intensity and quality. Dedicated photoreceptors help plants to perceive light signals of different wavelengths.

BBX31 promotes hypocotyl growth, primary root elongation and UV-B tolerance in Arabidopsis.

Photomorphogenesis is an important developmental process that helps the seedlings adapt to external light conditions. B-Box proteins are a family of transcription factors that regulate photomorphogenic responses. BBX31 negatively regulates photomorphogenesis under visible light.

The B-Box-Containing MicroProtein miP1a/BBX31 Regulates Photomorphogenesis and UV-B Protection.

The bZIP transcription factor ELONGATED HYPOCOTYL5 (HY5) represents a major hub in the light-signaling cascade both under visible and UV-B light. The mode of transcriptional regulation of , especially under UV-B light, is not well characterized. B-BOX (BBX) transcription factors regulate transcription and also posttranscriptionally modulate HY5 to control photomorphogenesis under white light.

The B-box bridge between light and hormones in plants.

Plant development is meticulously modulated by interactions between the surrounding environment and the endogenous phytohormones. Light, as an external signal coordinates with the extensive networks of hormones inside the plant to execute its effects on growth and development. Several proteins in plants have been identified for their crucial roles in mediating light regulated development.

Opposite roles of group IV BBX proteins: Exploring missing links between structural and functional diversity.

BBX proteins are a family of zinc finger transcription factors that are versatile regulators of plant development. The 32 BBX proteins in Arabidopsis are subdivided into five structural groups based on their domain structure. Members of group IV play important and diverse roles in light-regulated development.

Two B-Box Proteins Regulate Photomorphogenesis by Oppositely Modulating HY5 through their Diverse C-Terminal Domains.

The Arabidopsis () BBX family comprises several positive and negative regulators of photomorphogenesis. BBX24, a member of BBX structural group IV, acts as a negative regulator of photomorphogenesis, whereas another member from the same group, BBX21, is a positive regulator. The molecular basis for the functional diversity shown by these related BBX family members is unknown.