旨在揭示拟南芥CBL9(Calcineurin B-like protein 9)在花粉管顶端生长中的作用。基于花粉管瞬时表达体系,通过基因枪技术将带有黄色荧光蛋白(YFP)标签的CBL9在烟草花粉中进行瞬时表达,观察其亚细胞定位及过表达表型。针对CBL9的N端酰基...旨在揭示拟南芥CBL9(Calcineurin B-like protein 9)在花粉管顶端生长中的作用。基于花粉管瞬时表达体系,通过基因枪技术将带有黄色荧光蛋白(YFP)标签的CBL9在烟草花粉中进行瞬时表达,观察其亚细胞定位及过表达表型。针对CBL9的N端酰基化的保守位点,通过点突变技术构建CBL9G2A突变体,对比研究其表型及定位的改变情况。结果显示CBL9-YFP定位于花粉管顶端质膜及颗粒状细胞器上,CBL9过量表达可以引起显著的花粉管去极化生长。而CBL9G2A-YFP则表现出非特异性的胞内弥散定位,同时CBL9G2A过量表达没有显著影响花粉管的顶端生长。CBL9的N端酰基化位点是CBL9质膜定位的重要因素,而正确定位的CBL9才能发挥调控花粉管生长的相关功能。展开更多
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
The aim of this study was to establish a quality-control method for calcineurin subunit B(CNB) biological activity determinations. CNB enhances the p-nitrophenylphosphate(p NPP) dephosphorylating activity of calcineur...The aim of this study was to establish a quality-control method for calcineurin subunit B(CNB) biological activity determinations. CNB enhances the p-nitrophenylphosphate(p NPP) dephosphorylating activity of calcineurin subunit A Δ316 mutant(CNAΔ316). A series of CNB concentrations were fitted to a four-parameter equation to calculate the corresponding p NPP maximum dephosphorylation rates. Values were calculated based on biological activity references using a parallel line method. The method was then validated for accuracy, precision, linearity, linear range, sensitivity, specificity, and robustness. The recovery results were greater than 98%. Intra-plate precision was 6.7%, with inter-plate precision of 10.8%. The coefficient of determination was greater than 0.98. The linear range was 0.05–50 μg m L?1, with sensitivity of 50 μg m L?1. Tested cytokines did not induce CNAΔ316 dephosphorylation of p NPP. The chosen CNAΔ316 concentration range did not affect activity determinations.展开更多
文摘旨在揭示拟南芥CBL9(Calcineurin B-like protein 9)在花粉管顶端生长中的作用。基于花粉管瞬时表达体系,通过基因枪技术将带有黄色荧光蛋白(YFP)标签的CBL9在烟草花粉中进行瞬时表达,观察其亚细胞定位及过表达表型。针对CBL9的N端酰基化的保守位点,通过点突变技术构建CBL9G2A突变体,对比研究其表型及定位的改变情况。结果显示CBL9-YFP定位于花粉管顶端质膜及颗粒状细胞器上,CBL9过量表达可以引起显著的花粉管去极化生长。而CBL9G2A-YFP则表现出非特异性的胞内弥散定位,同时CBL9G2A过量表达没有显著影响花粉管的顶端生长。CBL9的N端酰基化位点是CBL9质膜定位的重要因素,而正确定位的CBL9才能发挥调控花粉管生长的相关功能。
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.
基金supported by the National Important Novel Medicine Research Project (2012ZX09304010, 2013ZX09102062)the National Natural Science Foundation of China (31270849)
文摘The aim of this study was to establish a quality-control method for calcineurin subunit B(CNB) biological activity determinations. CNB enhances the p-nitrophenylphosphate(p NPP) dephosphorylating activity of calcineurin subunit A Δ316 mutant(CNAΔ316). A series of CNB concentrations were fitted to a four-parameter equation to calculate the corresponding p NPP maximum dephosphorylation rates. Values were calculated based on biological activity references using a parallel line method. The method was then validated for accuracy, precision, linearity, linear range, sensitivity, specificity, and robustness. The recovery results were greater than 98%. Intra-plate precision was 6.7%, with inter-plate precision of 10.8%. The coefficient of determination was greater than 0.98. The linear range was 0.05–50 μg m L?1, with sensitivity of 50 μg m L?1. Tested cytokines did not induce CNAΔ316 dephosphorylation of p NPP. The chosen CNAΔ316 concentration range did not affect activity determinations.
