Physiological and biochemical traits in coriander affected by plant growth-promoting rhizobacteria under salt stress

Abstract

Salinity is a major environmental stress that limits crop production worldwide. It is well-understood that environmental adaptations, physiological and biochemical traits adjust salinity tolerance in plants, but imparting the knowledge gained towards crop improvement remain arduous. Utilizing the potentially of beneficial microorganisms present in the rhizosphere is an alternative strategy to improve crop production under optimal or stress conditions. The current study aims at examining the ability of plant growth-promoting rhizobacteria (PGPR) in improving coriander growth under salt stress condition. Coriander seeds were inoculated via dual culture of Azospirillum brasiliense and Azotobacter chroococcum , and therefore subjected to four levels of salt stress (0, 40, 80 and 120 mM NaCl) with three replications in a research greenhouse. Seventy-five days after sowing, when leaves fully developed, leaf samples were collected and the traits were measured. The results indicated that the dual inoculation improved chlorophyll a and b content, in comparison to the un-inoculated plants. The dual inoculation increased grain yield, stem fresh and dry weights by 11.6, 11.3 and 17.2%, respectively; it also enhanced total plant fresh and dry weights by 6.1 and 10.2%, respectively, as compared to control. As a result, the dual inoculation significantly improved catalase (CAT), but decreased ascorbate peroxidase (APX) and guaiacol peroxidase (GPX) enzymes activities, as compared to control plants. Salt stress significantly increased (CAT) activity in the leaves, whereas it resulted in significant reduction in (APX) and (GPX) activity, especially in inoculated plants. Furthermore, dual inoculation decreased Na and subsequently increased K concentration in coriander leaves comparing with untreated plants. Overall, these results indicate that the PGPRs has improved coriander growth under control as well as salt stress conditions. Thus, PGPR can could significantly contribute to solve the coriander plant production problems caused by high salinity.

Screening for drought tolerance potential of nine cocoa (Theobroma cacao L.) genotypes from Ghana

“…Plant growth promoting rhizobacteria (PGPR), has also been shown to increase tolerance of plants to drought stress ( Pereira et al., 2020 ). Rabiei et al. (2020) reported similar mechanism, using PGPR, to increase plant tolerance to salinity in ( Coriandrum sativum L ).…”

“…Plant growth promoting rhizobacteria (PGPR), has also been shown to increase tolerance of plants to drought stress (Pereira et al, 2020). Rabiei et al (2020) reported similar mechanism, using PGPR, to increase plant tolerance to salinity in (Coriandrum sativum L). Plant also use physiological characteristics to adapt to water stress environments through maintaining high water status regardless of soil moisture content (Zhang et al, 2018).…”

High Resistance of a Sludge Enriched with Nitrogen-Fixing Bacteria to Ammonium Salts and Its Potential as a Biofertilizer

“…Studies have shown that biofertilizer such as PGPRs together with salinity stress affect the growth, yield and physiology of coriander plants [ 14 ]. In our experiments, lower doses of adapted inoculum (T3) showed better plant properties and similar results to chemical fertilization (T2).…”

“…This trait is desirable for human coriander consumption but it can also be associated with soil plant stress due to salinity conditions. On the other hand, the height of plants is not directly correlated with type of fertilization [ 14 ].…”

“…These practices correspond to the use of soil organic amendments (which require sources of organic matter) but also of bioinoculants (plant growth-promoting rhizobacteria (PGPRs) or symbiotic fungi), in particular, isolated microorganisms [10,11]. These types of inoculants have decreased the use of chemical fertilizers by 10-20% [12][13][14] and take advantage of the microbial capacities of some soil microorganisms [15]. However, ammonium remnants and high salinity limit the persistence of bacteria and the long-term recovery of the NFB [15].…”