Abstract
BackgroundCold stress inhibits normal physiological metabolism in plants, thereby seriously affecting plant development. Meanwhile, plants also actively adjust their metabolism and development to adapt to changing environments. Several cold tolerance regulators have been found to participate in the regulation of plant development. Previously, we reported that BYPASS1-LIKE (B1L), a DUF793 family protein, participates in the regulation of cold tolerance, at least partly through stabilizing C-REPEAT BINDING FACTORS (CBFs). In this study, we found that B1L interacts with TRANSTHYRETIN-LIKE (TTL) protein, which is involved in brassinosteroid (BR)-mediated plant growth and catalyses the synthesis of S-allantoin, and both proteins participate in modulating plant growth and cold tolerance.ResultsThe results obtained with yeast two hybrid (Y2H) and bimolecular fluorescence complementation (BiFC) assays showed that B1L directly interacted with TTL. Similar to the ttl-1 and ttl-2 mutants, the b1l mutant displayed a longer hypocotyl and greater fresh weight than wild type, whereas B1L-overexpressing lines exhibited a shorter hypocotyl and reduced fresh weight. Moreover, ttl-1 displayed freezing tolerance to cold treatment compared with WT, whereas the b1l mutant and TTL-overexpressing lines were freezing-sensitive. The b1l ttl double mutant had a developmental phenotype and freezing tolerance that were highly similar to those of ttl-1 compared to b1l, indicating that TTL is important for B1L function. Although low concentrations of brassinolide (0.1 or 1 nM) displayed similarly promoted hypocotyl elongation of WT and b1l under normal temperature, it showed less effect to the hypocotyl elongation of b1l than to that of WT under cold conditions. In addition, the b1l mutant also contained less amount of allantoin than Col-0.ConclusionOur results indicate that B1L and TTL co-regulate development and cold tolerance in Arabidopsis, and BR and allantoin may participate in these processes through B1L and TTL.
Highlights
Cold stress inhibits normal physiological metabolism in plants, thereby seriously affecting plant development
We found that B1L interacts with TTL, and both of them participate in cold tolerance and in the regulation of plant growth
When B1L was fused with the Gal4 DNA binding domain (BD) and TTL was fused with the Gal4 activation domain (AD) and co-transformed into the yeast strain AH109, the Yeast two-hybrid (Y2H) assay showed that B1L interacted with TTL (Fig. 1a)
Summary
Cold stress inhibits normal physiological metabolism in plants, thereby seriously affecting plant development. We found that B1L interacts with TRANSTHYRETIN-LIKE (TTL) protein, which is involved in brassinosteroid (BR)-mediated plant growth and catalyses the synthesis of S-allantoin, and both proteins participate in modulating plant growth and cold tolerance. Large numbers of proteins have been found to play important roles in modulating plant cold tolerance [1,2,3] Among these proteins, several core regulators of cold tolerance, such as C-REPEAT BINDING FACTORS (CBFs) and INDUCER OF CBF EXPRESSION 1 (ICE1) [4,5,6,7], have been found to regulate diverse developmental processes [8,9,10,11,12,13,14,15]. TTL represents a regulator of plant growth and may perform important roles in stress tolerance
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
