1.
Noncoding-RNA-Mediated Regulation in Response to Macronutrient Stress in Plants.
Li, Z, Tian, P, Huang, T, Huang, J
International journal of molecular sciences. 2021;(20)
Abstract
Macronutrient elements including nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S) are required in relatively large and steady amounts for plant growth and development. Deficient or excessive supply of macronutrients from external environments may trigger a series of plant responses at phenotypic and molecular levels during the entire life cycle. Among the intertwined molecular networks underlying plant responses to macronutrient stress, noncoding RNAs (ncRNAs), mainly microRNAs (miRNAs) and long ncRNAs (lncRNAs), may serve as pivotal regulators for the coordination between nutrient supply and plant demand, while the responsive ncRNA-target module and the interactive mechanism vary among elements and species. Towards a comprehensive identification and functional characterization of nutrient-responsive ncRNAs and their downstream molecules, high-throughput sequencing has produced massive omics data for comparative expression profiling as a first step. In this review, we highlight the recent findings of ncRNA-mediated regulation in response to macronutrient stress, with special emphasis on the large-scale sequencing efforts for screening out candidate nutrient-responsive ncRNAs in plants, and discuss potential improvements in theoretical study to provide better guidance for crop breeding practices.
2.
Enhancing Butanol Production under the Stress Environments of Co-Culturing Clostridium acetobutylicum/Saccharomyces cerevisiae Integrated with Exogenous Butyrate Addition.
Luo, H, Ge, L, Zhang, J, Zhao, Y, Ding, J, Li, Z, He, Z, Chen, R, Shi, Z
PloS one. 2015;(10):e0141160
Abstract
In this study, an efficient acetone-butanol-ethanol (ABE) fermentation strategy integrating Clostridium acetobutylicum/Saccharomyces cerevisiae co-culturing system with exogenous butyrate addition, was proposed and experimentally conducted. In solventogenic phase, by adding 0.2 g-DCW/L-broth viable S. cerevisiae cells and 4.0 g/L-broth concentrated butyrate solution into C. acetobutylicum culture broth, final butanol concentration and butanol/acetone ratio in a 7 L anaerobic fermentor reached the highest levels of 15.74 g/L and 2.83 respectively, with the increments of 35% and 43% as compared with those of control. Theoretical and experimental analysis revealed that, the proposed strategy could, 1) extensively induce secretion of amino acids particularly lysine, which are favorable for both C. acetobutylicum survival and butanol synthesis under high butanol concentration environment; 2) enhance the utilization ability of C. acetobutylicum on glucose and over-produce intracellular NADH for butanol synthesis in C. acetobutylicum metabolism simultaneously; 3) direct most of extra consumed glucose into butanol synthesis route. The synergetic actions of effective amino acids assimilation, high rates of substrate consumption and NADH regeneration yielded highest butanol concentration and butanol ratio in C. acetobutylicum under this stress environment. The proposed method supplies an alternative way to improve ABE fermentation performance by traditional fermentation technology.
3.
Potassium nitrate application alleviates sodium chloride stress in winter wheat cultivars differing in salt tolerance.
Zheng, Y, Jia, A, Ning, T, Xu, J, Li, Z, Jiang, G
Journal of plant physiology. 2008;(14):1455-65
Abstract
A sand culture experiment was conducted to answer the question whether or not exogenous KNO(3) can alleviate adverse effects of salt stress in winter wheat by monitoring plant growth, K(+)/Na(+) accumulation and the activity of some antioxidant enzymes. Seeds of two wheat cultivars (CVs), DK961 (salt-tolerant) and JN17 (salt-sensitive), were planted in sandboxes and controls germinated and raised with Hoagland nutrient solution (6 mM KNO(3), no NaCl). Experimental seeds were exposed to seven modified Hoagland solutions containing increased levels of KNO(3) (11, 16, 21 mM) or 100 mM NaCl in combination with the four KNO(3) concentrations (6, 11, 16 and 21 mM). Plants were harvested 30 d after imbibition, with controls approximately 22 cm in height. Both CVs showed significant reduction in plant height, root length and dry weight of shoots and roots under KNO(3) or NaCl stress. However, the combination of increased KNO(3) and NaCl alleviated symptoms of the individual salt stresses by improving growth of shoots and roots, reducing electrolyte leakage, malondialdehyde and soluble sugar contents and enhancing the activities of antioxidant enzymes. The salt-tolerant cultivar accumulated more K(+) in both shoots and roots compared with the higher Na(+) accumulation typical for the salt-sensitive cultivar. Soluble sugar content and activities of antioxidant enzymes were found to be more stable in the salt-tolerant cultivar. Our findings suggest that the optimal K(+)/Na(+) ratio of the nutrient solution should be 16:100 for both the salt-tolerant and the salt-sensitive cultivar under the experimental conditions used, and that the alleviation of NaCl stress symptoms through simultaneously applied elevated KNO(3) was more effective in the salt-tolerant than in the salt-sensitive cultivar.