Abstract
Nitrate signaling integrates and coordinates gene expression and plant growth; however, the underlying molecular mechanisms involved remain poorly understood. Our previous study revealed that rice calcineurin B-like protein 1 (OsCBL1) modulates lateral root elongation by affecting auxin biosynthesis. Here, we report that OsCBL1 also modulates nitrate signaling to regulate rice seedlings growth. Compared with wild-type seedlings, seedlings of OsCBL1-knockdown (OsCBL1-KD) plants showed a suppressed growth phenotype, which included reduced root and shoot fresh weights and shorter radicles, crown roots, and lateral roots, when grown in nitrogen-free conditions. Although the growth defects of OsCBL1-KD plants could be partially rescued by the addition of nitrate to the growth conditions, the nitrate uptake capability of the OsCBL1-KD plants did not differ from that of wild-type plants as assessed via nitrate content and 15NO3− influx experiments. The nitrate-regulated expression of nitrate signal sentinel genes (OsNRT2.1 and OsNRT2.2) was affected in the OsCBL1-KD plants under both long- and short-term nitrate treatments. Overall, our results showed a novel role for OsCBL1 in the regulation of nitrate signaling and nitrate-mediated rice growth.
Highlights
Because they cannot escape from harsh environmental conditions like animals can, plants have evolved a sophisticated system to sense and adapt to changes in their surrounding environment, including nutrient variations
Our previous study showed that decreasing the expression of OsCBL1 (i.e., OsCBL1-KD) inhibited the growth of rice roots under 1/2-strength Murashige and Skoog (MS) medium growth conditions [15]
The CBL1 gene has been reported to be involved in the uptake of K+ and NH4+ in Arabidopsis [17, 18]; OsCBL1 localizes to the plasma membrane, and CBL1 is involved in the regulation of K+ uptake in rice [19]
Summary
Because they cannot escape from harsh environmental conditions like animals can, plants have evolved a sophisticated system to sense and adapt to changes in their surrounding environment, including nutrient variations. To further study how OsCBL1 participates in the regulation of rice growth and development and whether the regulation is related to the uptake of nutrient elements, we compared the growth of WT and OsCBL1-KD plants in H2O and in solution with different concentrations of NO3−.
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.
