Enhancement of disease resistance, growth potential, and photosynthesis in tomato (Solanum lycopersicum) by inoculation with an endophytic actinobacterium, Streptomyces thermocarboxydus strain BPSAC147

Abstract

Biotic stresses in plants have a significant impact on agricultural productivity. In the present study, in vivo experiments were conducted to determine the physiological responses of tomato ( Solanum lycopersicum L.) seedlings by inoculation with an endophytic actinobacterium, Streptomyces thermocarboxydus isolate BPSAC147 under greenhouse conditions. Further, photochemical quantum yield of photosystem II (PSII) (F v /F m ), photochemical quenching (qP) and non-photochemical (NPQ) were calculated in seedlings inoculated with S . thermocarboxydus (T1) and were compared with control (T0) plants. Furthermore, the electron transport rate (ETR) of PSII exhibited a significant increase in T1 plants, relative to T0 plants. These results indicate that inoculation of tomato seedlings with S . thermocarboxydus had a positive effect on the process of photosynthesis, resulting in enhanced chlorophyll fluorescence parameters due to increased ETR in the thylakoid membrane. GC-MS analysis showed significant differences in the volatile compounds in the different treatments performed under greenhouse conditions. The present study suggests that S . thermocarboxydus can be used as new biocontrol agent to control Fusarium wilt in tomato crops and enhance productivity by enhancing photosynthesis.

Fusarium wilt biocontrol and tomato growth stimulation, using endophytic bacteria naturally associated with Solanum sodomaeum and S. bonariense plants

“…Several questions regarding the association of endophytic microorganisms with host plants, however, are still unanswered, including how long do they reside in the host and do they have any impact on photosynthesis. It appears evident that microbes can augment biotic stress tolerance in plants through the PGPB process (Passari et al 2019). Indeed, PGPB are known to produce various enzymes including amylase, chitinase, cellulase, invertase, lipase, keratinase, peroxidase, pectinase, protease, phytase, and xylanase which transform the complex nutrients into simple mineral forms.…”

“…These endophytes colonize plant parts without causing any adverse effects. On many hosts, they act as plant growth-promoting, and/or biocontrol agents by direct antagonism or via the host by triggering induced resistance (Constantin et al 2019;Passari et al 2019). For instance, endophytic bacteria namely, Bacillus mojavensis was shown able to promote growth of maize plants infected with Fusarium verticillioides (Kalai-Grami et al 2014).…”

Trichomes form genotype-specific microbial hotspots in the phyllosphere of tomato

“…They are well-known as an important source of bioactive natural products [53,54]. A recent study by Passari et al (2019) demonstrated that inoculation of tomato plants with Streptomycesthermocarboxydus (Actinobacteria) had a positive effect on plant growth, conferred protection against plant pathogen as well as production of carotenoids, benzenoids and avonoids [55]. Our results show that distinct plant-protecting taxa as well as enriched diversity might accumulate at this potential entry point for pathogens.…”

In Vivo Studies of Inoculated Plants and In Vitro Studies Utilizing Methanolic Extracts of Endophytic Streptomyces sp. Strain DBT34 Obtained from Mirabilis jalapa L. Exhibit ROS-Scavenging and Other Bioactive Properties

“…These findings are accordance with the results obtained in the current study, where DPPH and ABTS scavenging activity in chickpea plants were assessed. Even though numerous in-vivo pot experiments studies have already been reported on the ability of endophytic Actinobacteria [ 52 ] or other bacteria [ 53 ] to promote growth in a variety of plants, only a few of these studies also assessed antioxidant potential. Recently, Wang et al [ 54 ], studied the effect of endophytic Streptomyces chartreusis WZS021 on two sugarcane varieties under stress conditions and found that this Actinobacterium improved the stress tolerance of the host plant by regulating antioxidant levels.…”