scholarly journals The Effect of Plant Growth Promoting Rhizobacteria (PGPR), Salicylic Acid and Drought Stress on Growth Indices, the Chlorophyll and Essential Oil of Hyssop (Hyssopus officinalis)

2017 ◽  
Vol 14 (3) ◽  
pp. 1033-1042 ◽  
Author(s):  
Parisa Sharifi

ABSTRACT: The side effects of chemical drugs and the human tendency to make greater use of natural products in order to keep their health as well as problems of modern medical system caused more attention of human to medicinal plants. Hyssop (Hyssopus officinalis) is a plant of the family Lamiaceae and is one of the most important medicinal plants containing essential oils. Despite of the other crops, medicinal plants are the plants that quality of materials compared to their quantity is much more important and necessary. Today using symbiotic microorganisms with plants as the bio-fertilizer for providing nutrients is considered. Among plant growth promoting rhizobacteria, Azospirillum, Pseudomonas and Bacillus can be pointed out. It was observed that using the bio-fertilizer Nitroxin and phosphate solubilizing bacteria on Chamomile increased vegetative yield, seed yield and essential oil yield. In order to study the effect of PGPR, salicylic acid and drought stress on growth indices, the chlorophyll and essential oil of hyssop,a factorial based on a completely randomized design with three replications was conducted at the research greenhouse, Faculty of Agriculture, … University, during 2013- 2014. Treatments were drought stress, salicylic acid and PGPR. Results showed that drought stress reduced the growth and physiologic characteristics and increased essential oil percentand accordingly Hyssop essential oil yield increased. Also, salicylic acid caused the increase in the yield, physiologic and essential oil traits and avoided stress injuries and compensateddecrease in growth traits. Growth promoting bacteria by producing some metabolites such as growth regulators, or types of vitamins as well as improved access to nutrients were directly increase plant growthand development. Among used bacteria, Azospirillum had the greatest impact on improving the measured traits.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Elsayed Mansour ◽  
Hany A. M. Mahgoub ◽  
Samir A. Mahgoub ◽  
El-Sayed E. A. El-Sobky ◽  
Mohamed I. Abdul-Hamid ◽  
...  

AbstractWater deficit has devastating impacts on legume production, particularly with the current abrupt climate changes in arid environments. The application of plant growth-promoting rhizobacteria (PGPR) is an effective approach for producing natural nitrogen and attenuating the detrimental effects of drought stress. This study investigated the influence of inoculation with the PGPR Rhizobium leguminosarum biovar viciae (USDA 2435) and Pseudomonas putida (RA MTCC5279) solely or in combination on the physio-biochemical and agronomic traits of five diverse Vicia faba cultivars under well-watered (100% crop evapotranspiration [ETc]), moderate drought (75% ETc), and severe drought (50% ETc) conditions in newly reclaimed poor-fertility sandy soil. Drought stress substantially reduced the expression of photosynthetic pigments and water relation parameters. In contrast, antioxidant enzyme activities and osmoprotectants were considerably increased in plants under drought stress compared with those in well-watered plants. These adverse effects of drought stress reduced crop water productivity (CWP) and seed yield‐related traits. However, the application of PGPR, particularly a consortium of both strains, improved these parameters and increased seed yield and CWP. The evaluated cultivars displayed varied tolerance to drought stress: Giza-843 and Giza-716 had the highest tolerance under well-watered and moderate drought conditions, whereas Giza-843 and Sakha-4 were more tolerant under severe drought conditions. Thus, co-inoculation of drought-tolerant cultivars with R. leguminosarum and P. putida enhanced their tolerance and increased their yield and CWP under water-deficit stress conditions. This study showed for the first time that the combined use of R. leguminosarum and P. putida is a promising and ecofriendly strategy for increasing drought tolerance in legume crops.


2019 ◽  
Vol 8 (3) ◽  
pp. 221-228
Author(s):  
Aneela Riaz ◽  
Munazza Rafique ◽  
Muhammad Aftab ◽  
M. Amjad Qureshi ◽  
Hina Javed ◽  
...  

2019 ◽  
Vol 21 (1) ◽  
pp. 50 ◽  
Author(s):  
Lorena del Rosario Cappellari ◽  
Maricel Valeria Santoro ◽  
Axel Schmidt ◽  
Jonathan Gershenzon ◽  
Erika Banchio

The effects of plant inoculation with plant growth-promoting rhizobacteria (PGPR) and those resulting from the exogenous application of salicylic acid (SA) or methyl jasmonte (MeJA) on total phenolic content (TPC) and monoterpenes in Mentha x piperita plants were investigated. Although the PGPR inoculation response has been studied for many plant species, the combination of PGPR and exogenous phytohormones has not been investigated in aromatic plant species. The exogenous application of SA produced an increase in TPC that, in general, was of a similar level when applied alone as when combined with PGPR. This increase in TPC was correlated with an increase in the activity of the enzyme phenylalanine ammonia lyase (PAL). Also, the application of MeJA at different concentrations in combination with inoculation with PGPR produced an increase in TPC, which was more relevant at 4 mM, with a synergism effect being observed. With respect to the main monoterpene concentrations present in peppermint essential oil (EO), it was observed that SA or MeJA application produced a significant increase similar to that of the combination with rhizobacteria. However, when plants were exposed to 2 mM MeJA and inoculated, an important increase was produced in the concentration on menthol, pulegone, linalool, limonene, and menthone concentrations. Rhizobacteria inoculation, the treatment with SA and MeJA, and the combination of both were found to affect the amount of the main monoterpenes present in the EO of M. piperita. For this reason, the expressions of genes related to the biosynthesis of monoterpene were evaluated, with this expression being positively affected by MeJA application and PGPR inoculation, but was not modified by SA application. Our results demonstrate that MeJA or SA application combined with inoculation with PGPR constitutes an advantageous management practice for improving the production of secondary metabolites from M. piperita.


2019 ◽  
Vol 47 (3) ◽  
Author(s):  
Vladimir Ion ROTARU ◽  
Luxita RISNOVEANU

The growth of legume plants is usually improved by the rhizobacteria inoculation under low phosphorus (P) and alleviation of P nutrition plays important role in plant drought stress response. The aim of this study was to assess the comparative efficacy of two plant growth promoting rhizobacteria namely Burkholderia cepacia B36 and Enterobacter radicincitans D5/23T combined with two sources of phosphates in soybean (Glycine max L.) under low water supply. Plants were grown under P soluble versus insoluble P fertilization for comparing the effects of soybean inoculation on growth, uptake and use efficiency of phosphorus under moderate drought stress. At the beginning of flowering, half of plants was subjected to low water supply (35% water holding capacity, WHC) for 12 days while control plants were well watered - 70% WHC. The plants were harvested at the end of drought and physiological traits and P contents were analyzed. The inoculation treatments showed better plant growth and nutrient uptake when compared to uninoculated control. The application of the Burkholderia cepacia was more efficiently in terms plant growth than E. radicincitans especially under insoluble phosphates. Phosphorus concentrations of shoots and roots increased with both bacterial strains. The bacterial inoculation has much better stimulatory effect on nutrient uptake by soybean fertilized with insoluble phosphates. Study findings indicate that the combined application of PGPR (Burkholderia cepacia B36) and P amendments has the potential to improve P nutrition and growth of soybean cultivated on P-deficient soil under well-watered as well as moderate drought condition.   ********* In press - Online First. Article has been peer reviewed, accepted for publication and published online without pagination. It will receive pagination when the issue will be ready for publishing as a complete number (Volume 47, Issue 3, 2019). The article is searchable and citable by Digital Object Identifier (DOI). DOI link will become active after the article will be included in the complete issue. *********


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