scholarly journals PGPR Modulation of Secondary Metabolites in Tomato Infested with Spodoptera litura

Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 778 ◽  
Author(s):  
Bani Kousar ◽  
Asghari Bano ◽  
Naeem Khan

The preceding climate change demonstrates overwintering of pathogens that lead to increased incidence of insects and pest attack. Integration of ecological and physiological/molecular approaches are imperative to encounter pathogen attack in order to enhance crop yield. The present study aimed to evaluate the effects of two plant growth promoting rhizobacteria (Bacillus endophyticus and Pseudomonas aeruginosa) on the plant physiology and production of the secondary metabolites in tomato plants infested with Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae). The surface sterilized seeds of tomato were inoculated with plant growth promoting rhizobacteria (PGPR) for 3–4 h prior to sowing. Tomato leaves at 6 to 7 branching stage were infested with S. litura at the larval stage of 2nd instar. Identification of secondary metabolites and phytohormones were made from tomato leaves using thin-layer chromatography (TLC) and high performance liquid chromatography (HPLC) and fourier-transform infrared spectroscopy (FTIR). Infestation with S. litura significantly decreased plant growth and yield. The PGPR inoculations alleviated the adverse effects of insect infestation on plant growth and fruit yield. An increased level of protein, proline and sugar contents and enhanced activity of superoxide dismutase (SOD) was noticed in infected tomato plants associated with PGPR. Moreover, p-kaempferol, rutin, caffeic acid, p-coumaric acid and flavonoid glycoside were also detected in PGPR inoculated infested plants. The FTIR spectra of the infected leaf samples pre-treated with PGPR revealed the presence of aldehyde. Additionally, significant amounts of indole-3-acetic acid (IAA), salicylic acid (SA) and abscisic acid (ABA) were detected in the leaf samples. From the present results, we conclude that PGPR can promote growth and yield of tomatoes under attack and help the host plant to combat infestation via modulation in IAA, SA, ABA and other secondary metabolites.

Agronomy ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 2065
Author(s):  
Hammad Anwar ◽  
Xiukang Wang ◽  
Azhar Hussain ◽  
Muhammad Rafay ◽  
Maqshoof Ahmad ◽  
...  

Plant growth-promoting rhizobacteria with multiple growth-promoting traits play a significant role in soil to improve soil health, crop growth and yield. Recent research studies have focused on the integration of organic amendments with plant growth-promoting rhizobacteria (PGPR) to enhance soil fertility and reduce the hazardous effects of chemical fertilizers. This study aims to evaluate the integrated application of biochar, compost, fruit and vegetable waste, and Bacillus subtilis (SMBL 1) to soil in sole application and in combined form. The study comprises eight treatments—four treatments without inoculation and four treatments with SMBL 1 inoculation in a completely randomized design (CRD), under factorial settings with four replications. The results indicate that the integrated treatments significantly improved okra growth and yield compared with sole applications. The integration of SMBL 1 with biochar showed significant improvements in plant height, root length, leaf chlorophyll a and b, leaf relative water content, fruit weight, diameter and length by 29, 29, 50, 53.3, 4.3, 44.7 and 40.4%, respectively, compared with control. Similarly, fruit N, P and K contents were improved by 33, 52.7 and 25.6% and Fe and Zn in shoot were 37.1 and 35.6%, respectively, compared with control. The results of this study reveal that the integration of SMBL 1 with organic amendments is an effective approach to the sustainable production of okra.


2021 ◽  
Vol 44 (2) ◽  
pp. 69-84
Author(s):  
Farhana Tasnim Chowdhury ◽  
Nazia Rifat Zaman ◽  
Mohammad Riazul Islam ◽  
Haseena Khan

Plant growth promoting rhizobacteria (PGPR) residing in soil rhizosphere provide enormous beneficial effects to a plant host producing diverse secondary metabolites and enzymes useful for plant growth and protection. Siderophores, antibiotics, volatile compounds and hydrolytic enzymes are the major molecules secreted by the PGPRs, which have substantial antifungal properties and can provide plant protection. These compounds are responsible for the lysis and hyperparasitism of antagonists against deleterious fungal pathogens. Siderophore-producing PGPRs function by depriving the pathogen of iron nutrition. Antibiotics have been reported to be involved in the suppression of different fungal pathogens by inducing fungistasis, inhibition of spore germination, lysis of fungal mycelia. The PGPRs also secrete a wide range of low molecular weight volatile organic compounds (VOCs) that inhibit mycelial growth, sporulation, germination of phytophathogenic fungi, etc. Hydrolytic enzymes, mostly chitinase, protease and cellulose, lyse the cell wall of fungi. Therefore, plant growth-promoting rhizobacteria can be considered as an effective, eco-friendly, and sustainable replacement to the chemical fungicides. There are many PGPRs that perform very well in controlled conditions but not in field conditions, and hence the commercializing of hese products is not easy.  Development of formulations with increased shelf life, a broad spectrum of action and consistent performance under field conditions can pave the way for commercializing the PGPRs at a faster rate. Journal of Bangladesh Academy of Sciences, Vol. 44, No. 2, 69-84, 2020


2021 ◽  
Author(s):  
Rafia Younas ◽  
Shiza Gul ◽  
Rehan Ahmad ◽  
Ali Raza Khan ◽  
Mumtaz Khan ◽  
...  

Global climate change is leading to a series of frequent onset of environmental stresses such as prolonged drought periods, dynamic precipitation patterns, heat stress, and cold stress on plants and commercial crops. The increasing severity of such stresses is not only making agriculture and related economic sector vulnerable but also negatively influences plant diversity patterns. The global temperature of planet Earth has risen to 1.1°C since the last 19th century. An increase in surface temperature leads to an increase in soil temperature which ultimately reduces water content in the soil, thereby, reducing crop growth and yield. Moreover, this situation is becoming more intense for agricultural practices in arid and semi-arid regions. To overcome climatically induced stresses, acclimatization of plant species via bioinoculation with Plant Growth Promoting Rhizobacteria (PGPR) is becoming an effective approach. The PGPR are capable of colonizing rhizosphere (exophytes) as well as plant organs (endophytes), where they trigger an accumulation of osmolytes for osmoregulation or improving gene expression of heat or cold stress proteins, or by signaling the synthesis of phytohormones, metabolites, proteins, and antioxidants to scavenge reactive oxygen species. Thus, PGPR exhibiting multiple plant growth-promoting traits can be employed via bioinoculants to improve the plant’s tolerance against unfavorable stress conditions.


Sign in / Sign up

Export Citation Format

Share Document