scholarly journals Chrysanthemum DgWRKY2 Gene Enhances Tolerance to Salt Stress in Transgenic Chrysanthemum

2018 ◽  
Vol 19 (7) ◽  
pp. 2062 ◽  
Author(s):  
Ling He ◽  
Yin-Huan Wu ◽  
Qian Zhao ◽  
Bei Wang ◽  
Qing-Lin Liu ◽  
...  

WRKY transcription factors (TFs) play a vital part in coping with different stresses. In this study, DgWRKY2 was isolated from Dendranthema grandiflorum. The gene encodes a 325 amino acid protein, belonging to the group II WRKY family, and contains one typical WRKY domain (WRKYGQK) and a zinc finger motif (C-X4-5-C-X22-23-H-X1-H). Overexpression of DgWRKY2 in chrysanthemum enhanced tolerance to high-salt stress compared to the wild type (WT). In addition, the activities of antioxidant enzymes (superoxide dismutase (SOD), peroxidase (POD), catalase (CAT)), proline content, soluble sugar content, soluble protein content, and chlorophyll content of transgenic chrysanthemum, as well as the survival rate of the transgenic lines, were on average higher than that of the WT. On the contrary, hydrogen peroxide (H2O2), superoxide anion (O2−), and malondialdehyde (MDA) accumulation decreased compared to WT. Expression of the stress-related genes DgCAT, DgAPX, DgZnSOD, DgP5CS, DgDREB1A, and DgDREB2A was increased in the DgWRKY2 transgenic chrysanthemum compared with their expression in the WT. In conclusion, our results indicate that DgWRKY2 confers salt tolerance to transgenic chrysanthemum by enhancing antioxidant and osmotic adjustment. Therefore, this study suggests that DgWRKY2 could be used as a reserve gene for salt-tolerant plant breeding.

2019 ◽  
Vol 20 (10) ◽  
pp. 2453
Author(s):  
Qian Zhao ◽  
Ling He ◽  
Bei Wang ◽  
Qinglin Liu ◽  
Yuanzhi Pan ◽  
...  

Soil salinity represents a major constraint in the growth of chrysanthemum. Therefore, improving salinity tolerance of chrysanthemum has become an important research direction in tolerance breeding. Multiprotein bridging factor 1 (MBF1) is an evolutionarily highly conserved transcriptional co-activator in archaea and eukaryotes and has been reported to play important roles to respond to abiotic stresses. Here, a MBF1 gene induced by salt stress was isolated and functionally characterized from Dendranthema grandiflorum and name as DgMBF1. Overexpression of DgMBF1 in chrysanthemum increased the tolerance of plants to high salt stress compared to wild type (WT). It also showed fewer accumulations of hydrogen peroxide (H2O2), superoxide anion (O2−), higher activities of antioxidant enzymes, more content of proline and soluble sugar (SS) and more favorable K+/Na+ ratio than those of WT under salt stress. In addition, the expression level of genes related to antioxidant biosynthesis, proline biosynthesis, glyco-metabolism and K+/Na+ homeostasis was statistically significant higher in the DgMBF1-overexpressed lines than that in WT. These results demonstrated that DgMBF1 is a positive regulator in response to salt stress and could serve as a new candidate gene for salt-tolerant plant breeding.


2018 ◽  
Vol 19 (12) ◽  
pp. 3936 ◽  
Author(s):  
Chuthamas Boonchai ◽  
Thanikarn Udomchalothorn ◽  
Siriporn Sripinyowanich ◽  
Luca Comai ◽  
Teerapong Buaboocha ◽  
...  

Rice nucleolin (OsNUC1), consisting of two isoforms, OsNUC1-L and OsNUC1-S, is a multifunctional protein involved in salt-stress tolerance. Here, OsNUC1-S’s function was investigated using transgenic rice lines overexpressing OsNUC1-S. Under non-stress conditions, the transgenic lines showed a lower yield, but higher net photosynthesis rates, stomatal conductance, and transpiration rates than wild type only in the second leaves, while in the flag leaves, these parameters were similar among the lines. However, under salt-stress conditions at the booting stage, the higher yields in transgenic lines were detected. Moreover, the gas exchange parameters of the transgenic lines were higher in both flag and second leaves, suggesting a role for OsNUC1-S overexpression in photosynthesis adaptation under salt-stress conditions. Moreover, the overexpression lines could maintain light-saturation points under salt-stress conditions, while a decrease in the light-saturation point owing to salt stress was found in wild type. Based on a transcriptome comparison between wild type and a transgenic line, after 3 and 9 days of salt stress, the significantly differentially expressed genes were enriched in the metabolic process of nucleic acid and macromolecule, photosynthesis, water transport, and cellular homeostasis processes, leading to the better performance of photosynthetic processes under salt-stress conditions at the booting stage.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ning Ouyang ◽  
Xuewu Sun ◽  
Yanning Tan ◽  
Zhizhong Sun ◽  
Dong Yu ◽  
...  

Remobilization of pre-anthesis NSCs (non-structural carbohydrates) is significant for effective grain filling in rice (Oryza sativa L.). However, abundant starch particles as an important component of NSCs are still present in the leaf sheath and stem at the late stage of grain filling. There are no studies on how bioengineering techniques can be used to improve the efficiency of NSC remobilization. In this study, RAmy1A was expressed under the senescence-specific promoter of SAG12, which was designed to degrade starch in the leaf sheath and stem during grain filling. RAmy1A mRNA successfully accumulated in the leaf, stem, and sheath of transgenic plants after anthesis. At the same time, the starch and total soluble sugar content in the leaf, stem, and leaf sheath were obviously decreased during the grain-filling period. The photosynthetic rate of transgenic lines was higher than that of the wild types by an average of 4.0 and 9.9%, at 5 and 10 days after flowering, respectively. In addition, the grain-filling rate of transgenic lines was faster than that of the wild types by an average of 26.09%. These results indicate an enhanced transport efficiency of NSCs from source tissues in transgenic rice. Transgenic rice also displayed accelerated leaf senescence, which was hypothesized to contribute to decreased grain weight.


Plants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 563 ◽  
Author(s):  
Stefan Timm ◽  
Franziska Woitschach ◽  
Carolin Heise ◽  
Martin Hagemann ◽  
Hermann Bauwe

Photorespiration metabolizes 2-phosphoglyolate (2-PG) to avoid inhibition of carbon assimilation and allocation. In addition to 2-PG removal, photorespiration has been shown to play a role in stress protection. Here, we studied the impact of faster 2-PG degradation through overexpression of 2-PG phosphatase (PGLP) on the abiotic stress-response of Arabidopsis thaliana (Arabidopsis). Two transgenic lines and the wild type were subjected to short-time high light and elevated temperature stress during gas exchange measurements. Furthermore, the same lines were exposed to long-term water shortage and elevated temperature stresses. Faster 2-PG degradation allowed maintenance of photosynthesis at combined light and temperatures stress and under water-limiting conditions. The PGLP-overexpressing lines also showed higher photosynthesis compared to the wild type if grown in high temperatures, which also led to increased starch accumulation and shifts in soluble sugar contents. However, only minor effects were detected on amino and organic acid levels. The wild type responded to elevated temperatures with elevated mRNA and protein levels of photorespiratory enzymes, while the transgenic lines displayed only minor changes. Collectively, these results strengthen our previous hypothesis that a faster photorespiratory metabolism improves tolerance against unfavorable environmental conditions, such as high light intensity and temperature as well as drought. In case of PGLP, the likely mechanism is alleviation of inhibitory feedback of 2-PG onto the Calvin–Benson cycle, facilitating carbon assimilation and accumulation of transitory starch.


Author(s):  
Honglian Ge

This study was aimed to investigate the potential of Azotobacter sp. strain AC11 in promoting growth and enhancing resistance to salinity stress in tomato seedlings. In this study, we measured the ability of strain AC11 to fix nitrogen and solubilize phosphorus and potassium, as well as its production of indole-3-acetic acid (IAA) and siderophores. A greenhouse pot experiment was conducted to investigate whether strain AC11 promoted tomato seedlings’ growth and enhanced their salt resistance. The results showed that strain AC11 produced IAA and siderophores, fixed nitrogen, and solubilized potassium and phosphorus. In pot trials, strain AC11 increased the shoot height, root length, and dry and fresh weights of tomato seedlings, and also increased their chlorophyll, soluble protein, and soluble sugar content. Furthermore, the bacteria induced the activities of superoxide dismutase (SOD; EC: 1.15.1.1), peroxidase (POD; EC: 1.11.1.7), and catalase (CAT; EC: 1.11.1.6), while it reduced the malondialdehyde (MDA) content and rate of O2- generation in tomato seedlings under salt stress. In summary, Azotobacter sp. strain AC11 promoted the growth of tomato seedlings and induced resistance to salt stress by producing IAA and siderophores, promoting the activities of antioxidant enzymes, and increasing the content of osmotic adjustment substances as well as enhancing the availability of the macronutrients N, P, K, and Fe3+ in the soil.


PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12478
Author(s):  
Baike Wang ◽  
Ning Li ◽  
Shaoyong Huang ◽  
Jiahui Hu ◽  
Qiang Wang ◽  
...  

Soluble sugar is known to improve the sweetness and increase tomato sauce yield. Studies have focused on improving the content of soluble sugar in tomato fruits, usually by promoting functional genes. We studied two genes (SlINVINH1 and SlVPE5) that inhibited the accumulation of soluble sugar in tomato fruits and obtained two genes’ knocked-out lines (CRISPR-invinh1 or CRISPR-vpe5) using CRISPR/Cas9. Aggregated lines with CRISPR-invinh1 and CRISPR-vpe5 were gained by hybridization and self-pollination. Compared to wild-type lines, the glucose, fructose, and total soluble solid (TSS) contents of CRISPR-invinh1 and CRISPR-vpe5 increased significantly. Glucose, fructose, and TSS levels further improved simultaneously with CRISPR-invinh1 and CRISPR-vpe5 than with single gene knock-out lines. This indicates that these genes have a synergistic effect and will increase the soluble sugar content. Thus, the knock-out SlINVINH1 and SlVPE5 may provide a practical basis for improving the sweetness of tomato fruits and their processing quality.


1998 ◽  
Vol 180 (4) ◽  
pp. 773-784 ◽  
Author(s):  
Fitnat H. Yildiz ◽  
Gary K. Schoolnik

ABSTRACT Vibrio cholerae is known to persist in aquatic environments under nutrient-limiting conditions. To analyze the possible involvement of the alternative sigma factor encoded byrpoS, which is shown to be important for survival during nutrient deprivation in several other bacterial species, a V. cholerae rpoS homolog was cloned by functional complementation of an Escherichia coli mutant by using a wild-type genomic library. Sequence analysis of the complementing clone revealed an 1.008-bp open reading frame which is predicted to encode a 336-amino-acid protein with 71 to 63% overall identity to other reported rpoS gene products. To determine the functional role of rpoS in V. cholerae, we inactivatedrpoS by homologous recombination. V. choleraestrains lacking rpoS are impaired in the ability to survive diverse environmental stresses, including exposure to hydrogen peroxide, hyperosmolarity, and carbon starvation. These results suggest that rpoS may be required for the persistence of V. cholerae in aquatic habitats. In addition, the rpoSmutation led to reduced production or secretion of hemagglutinin/protease. However, rpoS is not critical for in vivo survival, as determined by an infant mouse intestinal competition assay.


Plants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2181
Author(s):  
Sung-Il Kim ◽  
Kyu Ho Lee ◽  
Jun Soo Kwak ◽  
Dae Hwan Kwon ◽  
Jong Tae Song ◽  
...  

Small peptides and proteins play critical regulatory roles in plant development and environmental stress responses; however, only a few of these molecules have been identified and characterized to date because of their poor annotation and other experimental challenges. Here, we present that rice (Oryza sativa L.) OsS1Fa1, a small 76-amino acid protein, confers drought stress tolerance in Arabidopsis thaliana. OsS1Fa1 was highly expressed in leaf, culm, and root tissues of rice seedlings during vegetative growth and was significantly induced under drought stress. OsS1Fa1 overexpression in Arabidopsis induced the expression of selected drought-responsive genes and enhanced the survival rate of transgenic lines under drought. The proteasome inhibitor MG132 protected the OsS1Fa1 protein from degradation. Together, our data indicate that the small protein OsS1Fa1 is induced by drought and is post-translationally regulated, and the ectopic expression of OsS1Fa1 protects plants from drought stress.


2014 ◽  
Vol 1010-1012 ◽  
pp. 1225-1229
Author(s):  
Ming Xia Zhu ◽  
Feng Jin ◽  
Xi Wen Shao ◽  
Xian Ying Gao ◽  
Yan Qiu Geng ◽  
...  

Taking Changbai 9 and Changbai 22 as experiment material, using pot experiment, to study of different concentration effect of saline alkali stress on physiological characteristics of rice in different growth periods. The results showed that, effect of saline alkali stress on the physiological characteristics of the same rice variety and soil characteristics of different resistant rice varieties are different. Weak salt resistance of Changbai 22 of chlorophyll , soluble sugar and MDA of salt stress more sensitive than saline resistance strong of Changbai 9,and the change trend of the physiological indexes of two cultivars under saline alkali stress is consistent, with the increasing concentration of salt stress, leaf chlorophyll content, soluble sugar content and soluble protein content firstly increased and then decreased,while the MDA concentration showed an increasing trend. At the same time with the increase of salt stress concentration, accumulation of soluble sugar in leaves of Changbai 9 increased even more than Changbai 22,indicating the Changbai 9 may be mainly through the accumulation of soluble sugar to alleviate the toxic effects of osmotic stress. This study can be used as an important reference index for soda saline alkali soil rice planting, soil improvement and comprehensive utilization.


Sign in / Sign up

Export Citation Format

Share Document