CONSTANS (CO), a well-known member of the B-box family, is a major component of photoperiodically regulated flowering and circadian pathways in Arabidopsis (Arabidopsis thaliana). CO is expressed in various tissues, including seedling roots and young leaves. However, the roles and underlying mechanisms of CO in modulating physiological processes outside of flowering remain unclear.
In a study published in Plant PhysiologyResearchers from the Xishuangbanna Tropical Botanical Garden (XTBG) of the Chinese Academy of Sciences showed that the CONSTANS protein negatively modulated salinity tolerance in Arabidopsis through physical interaction and resistance with abscisic acid-responsive element binding factor (ABF) transcription factors. under the long sun. condition.
The researchers first examined the spatial pattern of CO expression and found its transcripts in young leaves and seedling roots. They observed that CO transcription and protein levels decreased in salt-stressed seedlings.
They then performed phenotypic analyzes and found that CO negatively mediated salinity tolerance under long day (LD) conditions. Loss-of-function CO mutant seedlings were more tolerant to salinity stress, while over-expression of CO resulted in plants with reduced tolerance to salinity stress.
Genetic analysis revealed that the negative role of GIGANTEA (GI) in mediating salinity tolerance requires a functional CO protein. Further investigations showed that CO physically interacts with Abscisic Acid-Responsive Element Binding Factor1 (ABF1), ABF2, ABF3, and ABF4, which belong to a large family of basic leucine zipper domains.
These ABFs were positively associated with the modulation of salinity tolerance. CO suppressed the expression of several salinity-responsive genes and interfered with the transcriptional regulatory function of ABF3.
“Our results suggest that CO antagonists interact with ABFs to inhibit responses to salinity. This study provides a mechanistic understanding of how plant salinity tolerance is negatively regulated by CO acting. coupled with ABF transcription factors,” said Hu Yanru of XTBG.
More information:
Jiancan Du et al, CONSTANS interacts with and counteracts ABF transcription factors during salt stress under long day conditions, Plant Physiology (2023). DOI: 10.1093/plphys/kiad370
Awarded by the Chinese Academy of Sciences
Citation: CONSTANS protein negatively modulates salinity tolerance in arabidopsis, study shows (2023, July 4) retrieved on 4 July 2023 from https://phys.org/news/2023-07-constans- protein-negatively-modulates-salinity.html
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