Ascorbate peroxidase(APX) plays a key role in scavenging reactive oxygen species(ROS) in higher plants. However, there is very little information available on the APXs in kiwifruit(Actinidia), which is an economically...Ascorbate peroxidase(APX) plays a key role in scavenging reactive oxygen species(ROS) in higher plants. However, there is very little information available on the APXs in kiwifruit(Actinidia), which is an economically and nutritionally important horticultural crop with exceptionally high ascorbic acid(AsA) accumulation. This study aims to identify and characterize two cytosolic APX genes(AcAPX1 and AcAPX2) derived from A. chinensis ‘Hongyang’. The constitutive expression pattern was determined for both AcAPX1 and AcAPX2, and showed relatively higher expression abundances of AcAPX1 in leaf and AcAPX2 in root. Transcript levels of AcAPX1 and AcAPX2 were increased in kiwifruit roots treated with Na Cl. Subcellular localization assays using GFP-fusion proteins in Arabidopsis protoplasts showed that both AcAPX1 and AcAPX2 are targeted to the cytosol. Recombinant AcAPX1 or AcAPX2 proteins were successfully expressed in the prokaryotic expression system and their individual ascorbate peroxidase activities were determined. Finally, constitutive over-expression of AcAPX1 or AcAPX2 could dramatically increase total As A, glutathione level and salinity tolerance under Na Cl stress in Arabidopsis thaliana. Our findings revealed that cytosolic AcAPX1/2 may play an important protective role in the responses to unfavorable environmental stimuli in kiwifruit.展开更多
基金funded by the National Natural Science Foundation of China (31972474)the Natural Science Research Program of Universities of Anhui Province, China (K1832004)+2 种基金the Leading Talent Group Funding of Anhui Province, China (WRMR-2020-75)the Natural Science Foundation of Anhui Province, China (19232002)the Anhui Agriculture University Shennong Scholar Project, China (RC321901)。
文摘Ascorbate peroxidase(APX) plays a key role in scavenging reactive oxygen species(ROS) in higher plants. However, there is very little information available on the APXs in kiwifruit(Actinidia), which is an economically and nutritionally important horticultural crop with exceptionally high ascorbic acid(AsA) accumulation. This study aims to identify and characterize two cytosolic APX genes(AcAPX1 and AcAPX2) derived from A. chinensis ‘Hongyang’. The constitutive expression pattern was determined for both AcAPX1 and AcAPX2, and showed relatively higher expression abundances of AcAPX1 in leaf and AcAPX2 in root. Transcript levels of AcAPX1 and AcAPX2 were increased in kiwifruit roots treated with Na Cl. Subcellular localization assays using GFP-fusion proteins in Arabidopsis protoplasts showed that both AcAPX1 and AcAPX2 are targeted to the cytosol. Recombinant AcAPX1 or AcAPX2 proteins were successfully expressed in the prokaryotic expression system and their individual ascorbate peroxidase activities were determined. Finally, constitutive over-expression of AcAPX1 or AcAPX2 could dramatically increase total As A, glutathione level and salinity tolerance under Na Cl stress in Arabidopsis thaliana. Our findings revealed that cytosolic AcAPX1/2 may play an important protective role in the responses to unfavorable environmental stimuli in kiwifruit.
