Department of Biosciences, University of Wah, Wah Cantt, Pakistan.
Recent Pat Food Nutr Agric. 2020;11(2):124-136. doi: 10.2174/2212798410666190716162340.
The present investigation aimed to evaluate the role of Plant Growth- Promoting Rhizobacteria (PGPR) and Ag-nanoparticles on two varieties (American variety, Poinsett 76 and Desi variety, Sialkot selection) of cucumber plants.
Cucumber seeds prior to sowing, were inoculated with two strains of PGPR, Pseudomonas putida (KX574857) and Pseudomonas stutzeri (KX574858) at the rate of 106 cells/ml. Agnanoparticles (5ppm) were sprayed on the plant at early vegetative phase 27 d after sowing.
The proline, sugar, protein, phenolics, flavonoids, chlorophyll and carotenoids contents of leaves of plants and the activities of Phenylalanine Ammonia-Lyase (PAL), Superoxide Dismutase (SOD) and Catalase (CAT) were determined from leaves of plants at early vegetative phase. After 3 months of seeds sowing, Ag-nanoparticles enhanced the length of root but decreased the length of shoot and fresh weight of root and shoot as compared to control whereas, the leaf protein, proline, phenolics, flavonoids, chlorophyll b, total chlorophyll, sugar and Phenylalanine Ammonia-Lyase (PAL) activity of plants were increased significantly over control. Ag-nanoparticles also suppressed the effect of PGPR for root, shoot length but augmented the protein and phenolics contents of leaves of both the varieties.
The combined treatment of Ag-nanoparticles and PGPR enhanced flavonoids content of leaves and the activities of PAL, SOD and CAT in leaves of plants over control. Agnanoparticles effectively increased the Phenylalanine Ammonia-Lyase (PAL), Catalase (CAT) and superoxide dismutase (SOD) activities in leaves of both the varieties. Pseudomonas putida may be used either alone or in combination with Ag-nanoparticles to enhance the antioxidant and defense enzyme activities. Hence, the plant can tolerate the diseases and stresses in a much better way with higher protein and phenolics content.
本研究旨在评估植物促生根际细菌（PGPR）和银纳米粒子对两个黄瓜品种（美国品种 Poinsett76 和 Desi 品种 Sialkot 选择）的作用。
播种前，将黄瓜种子用两株 PGPR 菌株 Pseudomonas putida（KX574857）和 Pseudomonas stutzeri（KX574858）以 106 个细胞/ml 的浓度接种。播种后 27 天，在早期营养生长阶段将银纳米粒子（5ppm）喷洒在植物上。
在早期营养生长阶段，从植物叶片中测定叶片中脯氨酸、糖、蛋白质、酚类、类黄酮、叶绿素和类胡萝卜素含量以及苯丙氨酸氨解酶（PAL）、超氧化物歧化酶（SOD）和过氧化氢酶（CAT）的活性。播种 3 个月后，与对照相比，银纳米粒子增加了根的长度，但减少了茎和根和茎的鲜重，而植物的叶片蛋白质、脯氨酸、酚类、类黄酮、叶绿素 b、总叶绿素、糖和苯丙氨酸氨解酶（PAL）活性均显著高于对照。银纳米粒子还抑制了 PGPR 对根、茎长度的影响，但增加了两个品种叶片的蛋白质和酚类含量。
银纳米粒子和 PGPR 的联合处理增强了叶片中类黄酮的含量，以及叶片中 PAL、SOD 和 CAT 的活性。银纳米粒子有效提高了两个品种叶片中苯丙氨酸氨解酶（PAL）、过氧化氢酶（CAT）和超氧化物歧化酶（SOD）的活性。Pseudomonas putida 可以单独使用或与银纳米粒子联合使用，以提高抗氧化和防御酶的活性。因此，植物可以更好地耐受疾病和压力，同时具有更高的蛋白质和酚类含量。
