Potassium is one of the major macro-nutrients essential for a number of cellular processes in plants. Low potassium level in the soil represents a limiting factor for crop production. Recent studies have identified po...Potassium is one of the major macro-nutrients essential for a number of cellular processes in plants. Low potassium level in the soil represents a limiting factor for crop production. Recent studies have identified potassium transporters that are involved in potassium acquisition, and some of them are critical for potassium nutrition under low potassium conditions. However, little is understood on the molecular components involved in low potassium signaling and responses. We report here the identification ofa calcineurin B-like protein-interacting protein kinase （CIPK9） as a critical regulator of low potassium response in ,Arabidopsis. The CIPK9 gene was responsive to abiotic stress conditions, and its transcript was inducible in both roots and shoots by potassium deprivation. Disruption of CIPK9 function rendered the mutant plants hypersensitive to low potassium media. Further analysis indicated that K^＋ uptake and content were not affected in the mutant plants, implying CIPK9 in the regulation of potassium utilization or sensing processes.展开更多
Calcium plays a vital role as a second messenger in many signaling pathways in plants. The calcineurin B-like proteins （CBLs） represent a family of plant calcium-binding proteins that function in calcium signaling b...Calcium plays a vital role as a second messenger in many signaling pathways in plants. The calcineurin B-like proteins （CBLs） represent a family of plant calcium-binding proteins that function in calcium signaling by interacting with their interacting protein kinases （CIPKs）. In our previous study, we have reported a role for one of the CBLs （CBL9） and one of the CIPKs （CIPK3） in ABA signaling. Here, we have shown that CBL9 and CIPK3 physically and functionally interact with each other in regulating the ABA responses. The CBL9 and CIPK3 proteins interacted with each other in the yeast two- hybrid system and when expressed in plant cells. The double mutant cbl9cipk3 showed the similar hypersensitive response to ABA as observed in single mutants （cbl9 or cipk3）. The constitutively active form of CIPK3 genetically complemented the cbl9 mutant, indicating that CIPK3 function downstream of CBL9. Based on these findings, we conclude that CBL9 and CIPK3 act together in the same pathway for regulating ABA responses.展开更多
基金a grant from the National Science Foundation （USA） （to SL）.
文摘Potassium is one of the major macro-nutrients essential for a number of cellular processes in plants. Low potassium level in the soil represents a limiting factor for crop production. Recent studies have identified potassium transporters that are involved in potassium acquisition, and some of them are critical for potassium nutrition under low potassium conditions. However, little is understood on the molecular components involved in low potassium signaling and responses. We report here the identification ofa calcineurin B-like protein-interacting protein kinase （CIPK9） as a critical regulator of low potassium response in ,Arabidopsis. The CIPK9 gene was responsive to abiotic stress conditions, and its transcript was inducible in both roots and shoots by potassium deprivation. Disruption of CIPK9 function rendered the mutant plants hypersensitive to low potassium media. Further analysis indicated that K^＋ uptake and content were not affected in the mutant plants, implying CIPK9 in the regulation of potassium utilization or sensing processes.
文摘Calcium plays a vital role as a second messenger in many signaling pathways in plants. The calcineurin B-like proteins （CBLs） represent a family of plant calcium-binding proteins that function in calcium signaling by interacting with their interacting protein kinases （CIPKs）. In our previous study, we have reported a role for one of the CBLs （CBL9） and one of the CIPKs （CIPK3） in ABA signaling. Here, we have shown that CBL9 and CIPK3 physically and functionally interact with each other in regulating the ABA responses. The CBL9 and CIPK3 proteins interacted with each other in the yeast two- hybrid system and when expressed in plant cells. The double mutant cbl9cipk3 showed the similar hypersensitive response to ABA as observed in single mutants （cbl9 or cipk3）. The constitutively active form of CIPK3 genetically complemented the cbl9 mutant, indicating that CIPK3 function downstream of CBL9. Based on these findings, we conclude that CBL9 and CIPK3 act together in the same pathway for regulating ABA responses.
