scholarly journals Dephosphorylation of Nitrate Reductase Protein Regulates Growth of Rice and Adaptability to Low Temperature

2022 ◽  
Author(s):  
Ruicai Han ◽  
Chenyan Li ◽  
Huijie Li ◽  
Yupeng Wang ◽  
Xiaohua Pan ◽  
...  
Keyword(s):  
Low Temperature ◽  
Nitrate Reductase ◽  
Chlorophyll Content ◽  
Phosphorylation Site ◽  
Nitrate Assimilation ◽  
Normal Growth ◽  
Growth Conditions ◽  
Nitrogen Utilization ◽  
Utilization Efficiency ◽  
Transgenic Lines

Abstract Nitrate reductase (NR) is an important enzyme for nitrate assimilation in plants, and its activity is regulated by post-translational phosphorylation. To investigate the effect of NIA1 protein dephosphorylation on the growth of rice and its adaptability to low temperature, we analyzed phenotype, chlorophyll content, nitrogen utilization, and antioxidant capacity at low temperature in lines with a mutated NIA1 phosphorylation site (S532D and S532A), an OsNia1 over-expression line (OE), and wild-type Kitaake rice (WT). Plant height, dry matter weight, and chlorophyll content of S532D and S532A were lower than those of WT and OE under normal growth conditions but were higher than those of WT and OE at low temperature. Compared with WT and OE, the nitrite, H2O2, and MDA contents of S532D and S532A leaves were higher under normal growth conditions. The difference in leaf nitrite content between transgenic lines and WT was narrower at low temperature, especially in S532D and S532A, while H2O2 and MDA contents of S532D and S532A leaves were lower than those in WT and OE leaves. The NH4+-N and amino acid contents of S532D and S532A leaves were higher than those of WT and OE leaves under normal or low temperature. qRT-PCR results revealed that transcription levels of OsNrt2.4, OsNia2, and OsNADH-GOGAT were positively correlated with those of OsNia1, and the transcription levels of OsNrt2.4, OsNia2, and OsNADH-GOGAT were significantly higher in transgenic lines than in WT under both normal and low temperature. Phosphorylation of NR is a steady-state regulatory mechanism of nitrogen metabolism, and dephosphorylation of NIA1 protein improved NR activity and nitrogen utilization efficiency in rice. Excessive accumulation of nitrite under normal growth conditions inhibits the growth of rice; however, accumulation of nitrite is reduced at low temperature, enhancing the cold tolerance of rice.

scholarly journals Yellow nutsedge WRI3/4-like gene improves drought tolerance in Arabidopsis thaliana by promoting cuticular wax biosynthesis

2019 ◽  
Author(s):  
Chao Cheng ◽  
Shutong Hu ◽  
Yun Han ◽  
Di Xia ◽  
Bang-Lian Huang ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Drought Stress ◽  
Drought Tolerance ◽  
Normal Growth ◽  
Growth Conditions ◽  
Cuticular Wax ◽  
Expression Data ◽  
Yellow Nutsedge ◽  
Transgenic Lines ◽  
Simulated Drought

Abstract Using RACE PCR, full length WRI1-like gene was amplified from yellow nutsedge. Conserved domain and phylogenetic analyses suggested it as WRI3/4-like gene. Tissue-specific expression data showed the highest expression in leaves, followed by roots while the lowest expression was detected in tuber. Transgenic Arabidopsis plants expressing nutsedge WRI3/4-like gene showed significantly improved tolerance to both PEG-simulated drought stress and real dehydration, compared with the wild type (WT). Under normal growth conditions, the expressions of key fatty acid biosynthesis genes was not significantly different between WT and transgenic lines, while the expressions of genes involved in cuticular wax biosynthesis was significantly higher in transgenic lines compared with the WT. The PEG-simulated drought stress did not induce any significant change in the expression of fatty acid and wax biosynthesis genes in WT plants, while the expression of fatty acid and wax biosynthesis genes was significantly increased in transgenic lines compared with WT as well as unstressed transgenic control. The expression of TAG1, the gene involved in triacylglycerol (TAG) accumulation, was significantly lower in the transgenic lines than that in the WT in normal growth conditions. Drought stress slightly decreased the expression of TAG1 in the WT, but significantly lowered it in transgenic lines compared with its unstressed transgenic control and WT. Consistent with gene expression data, the cuticular wax content in Arabidopsis leaves was significantly higher in the transgenic lines than in the WT, while the oil content was not significantly different. Our results indicated that WRI3/4-like gene from Cyperus esculentus improves drought tolerance in Arabidopsis probably by promoting cuticular wax biosynthesis and, hence, could be a valuable target for improving drought tolerance in crops through recombinant DNA technology.

scholarly journals Posttranslational Regulation of Nitrate Assimilation in the Cyanobacterium Synechocystis sp. Strain PCC 6803

2005 ◽  
Vol 187 (2) ◽  
pp. 498-506 ◽  
Author(s):  
Masaki Kobayashi ◽  
Nobuyuki Takatani ◽  
Mari Tanigawa ◽  
Tatsuo Omata
Keyword(s):  
Nitrate Reductase ◽  
Nitrate Uptake ◽  
Wild Type Strain ◽  
Phosphorylation Site ◽  
Nitrate Assimilation ◽  
Synechococcus Elongatus ◽  
Posttranslational Regulation ◽  
Nitrate And Nitrite ◽  
Pcc 7942 ◽  
Pcc 6803

ABSTRACT Posttranslational regulation of nitrate assimilation was studied in the cyanobacterium Synechocystis sp. strain PCC 6803. The ABC-type nitrate and nitrite bispecific transporter encoded by the nrtABCD genes was completely inhibited by ammonium as in Synechococcus elongatus strain PCC 7942. Nitrate reductase was insensitive to ammonium, while it is inhibited in the Synechococcus strain. Nitrite reductase was also insensitive to ammonium. The inhibition of nitrate and nitrite transport required the PII protein (glnB gene product) and the C-terminal domain of NrtC, one of the two ATP-binding subunits of the transporter, as in the Synechococcus strain. Mutants expressing the PII derivatives in which Ala or Glu is substituted for the conserved Ser49, which has been shown to be the phosphorylation site in the Synechococcus strain, showed ammonium-promoted inhibition of nitrate uptake like that of the wild-type strain. The S49A and S49E substitutions in GlnB did not affect the regulation of the nitrate and nitrite transporter in Synechococcus either. These results indicated that the presence or absence of negative electric charge at the 49th position does not affect the activity of the PII protein to regulate the cyanobacterial ABC-type nitrate and nitrite transporter according to the cellular nitrogen status. This finding suggested that the permanent inhibition of nitrate assimilation by an S49A derivative of PII, as was previously reported for Synechococcus elongatus strain PCC 7942, is likely to have resulted from inhibition of nitrate reductase rather than the nitrate and nitrite transporter.

scholarly journals The Application of a Commercially Available Citrus-Based Extract Mitigates Moderate NaCl-Stress in Arabidopsis thaliana Plants

Plants ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1010
Author(s):  
Johannes Loubser ◽  
Paul Hills
Keyword(s):  
Arabidopsis Thaliana ◽  
Salt Stress ◽  
Chlorophyll Content ◽  
Normal Growth ◽  
Growth Conditions ◽  
Nacl Stress ◽  
Preliminary Evidence ◽  
Stomatal Conductivity ◽  
Expression Of Genes

Aims: The aim of this study was to assess the effect of BC204 as a plant biostimulant on Arabidopsis thaliana plants under normal and NaCl-stressed conditions. Methods: For this study, ex vitro and in vitro growth experiments were conducted to assess the effect of both NaCl and BC204 on basic physiological parameters such as biomass, chlorophyll, proline, malondialdehyde, stomatal conductivity, Fv/Fm and the expression of four NaCl-responsive genes. Results: This study provides preliminary evidence that BC204 mitigates salt stress in Arabidopsis thaliana. BC204 treatment increased chlorophyll content, fresh and dry weights, whilst reducing proline, anthocyanin and malondialdehyde content in the presence of 10 dS·m−1 electroconductivity (EC) salt stress. Stomatal conductivity was also reduced by BC204 and NaCl in source leaves. In addition, BC204 had a significant effect on the expression of salinity-related genes, stimulating the expression of salinity-related genes RD29A and SOS1 independently of NaCl-stress. Conclusions: BC204 stimulated plant growth under normal growth conditions by increasing above-ground shoot tissue and root and shoot growth in vitro. BC204 also increased chlorophyll content while reducing stomatal conductivity. BC204 furthermore mitigated moderate to severe salt stress (10–20 dS·m−1) in A. thaliana. Under salt stress conditions, BC204 reduced the levels of proline, anthocyanin and malondialdehyde. The exact mechanism by which this occurs is unknown, but the results in this study suggest that BC204 may act as a priming agent, stimulating the expression of genes such as SOS1 and RD29A.

scholarly journals Protein Phosphatase (PP2C9) Induces Protein Expression Differentially to Mediate Nitrogen Utilization Efficiency in Rice under Nitrogen-Deficient Condition

2018 ◽  
Vol 19 (9) ◽  
pp. 2827 ◽  
Author(s):  
Muhammad Waqas ◽  
Shizhong Feng ◽  
Hira Amjad ◽  
Puleng Letuma ◽  
Wenshan Zhan ◽  
...  
Keyword(s):  
Nitrate Reductase ◽  
Environmental Sustainability ◽  
Protein Phosphatase ◽  
Defense Mechanisms ◽  
Essential Element ◽  
Proteome Analysis ◽  
Nitrogen Utilization ◽  
Utilization Efficiency ◽  
Nitrogen Utilization Efficiency ◽  
2D Gel

Nitrogen (N) is an essential element usually limiting in plant growth and a basic factor for increasing the input cost in agriculture. To ensure the food security and environmental sustainability it is urgently required to manage the N fertilizer. The identification or development of genotypes with high nitrogen utilization efficiency (NUE) which can grow efficiently and sustain yield in low N conditions is a possible solution. In this study, two isogenic rice genotypes i.e., wild-type rice kitaake and its transgenic line PP2C9TL overexpressed protein phosphatase gene (PP2C9) were used for comparative proteomics analysis at control and low level of N to identify specific proteins and encoding genes related to high NUE. 2D gel electrophoresis was used to perform the differential proteome analysis. In the leaf proteome, 30 protein spots were differentially expressed between the two isogenic lines under low N level which were involved in the process of energy, photosynthesis, N metabolism, signaling, and defense mechanisms. In addition, we have found that protein phosphatase enhances nitrate reductase activation by downregulation of SnRK1 and 14-3-3 proteins. Furthermore, we showed that PP2C9TL exhibits higher NUE than WT due to higher activity of nitrate reductase. This study provides new insights on the rice proteome which would be useful in the development of new strategies to increase NUE in cereal crops.

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