Streptomyces sp. CLV45 from Fabaceae rhizosphere benefits growth of soybean plants

Abstract

Plant growth-promoting bacteria such as Streptomyces are an attractive alternative for increasing the sustainability of agricultural systems. In this study, Streptomyces isolates obtained from rhizosphere soil of plants in the family Fabaceae were characterized for their plant growth-promoting traits, including the production of siderophores, 1-aminocyclopropane-1-carboxylate (ACC) deaminase, indole-3-acetic acid (IAA), and phenazines. Soybean seeds were bacterized with selected isolates to test growth promotion. All isolates produced IAA, and the isolate CLV45 was the most efficient, reaching 398.53 mg of IAA per gram of cells. CLV41, CLV45, and CLV46 showed high activity for ACC deaminase whereas CLV42, CLV44, and CLV46 were efficient in siderophore production. Pyocyanin was detected in all isolates; CLV41, CLV43, and CLV45 produced phenazinecarboxylic acid as well. Selected for IAA and ACC deaminase production combined with production of siderophores and phenazines, CLV42, CLV44, and CLV45 were tested for their growth promotion potential. Seed bacterization with CLV45 resulted in plants with increased shoot growth (36.63%) and dry mass (17.97%) compared to control plants. Results suggest that moderate or high levels of auxin and ACC deaminase production by the isolate CLV45 positively affected the growth of soybean plants, making it a strong candidate for further studies on biofertilizer formulation.

Isolation, identification, and growth-promotion function of Streptomyces sp. in wetland rhizosphere

“…KLBMP 5084 secretes 8.24 μg/mL IAA, which promotes seed germination and seedling growth of Limonium sinense (Qin et al 2014), whereas Streptomyces sp. CLV45 secretes as much as 398.53 μg/mL IAA, which promotes the growth of soybean plants (Horstmann et al 2020).…”

“…All seedlings were irrigated once every 3 days. After 15 days, physiological indicators, such as plant height, root length, lateral root number, and fresh weight, were measured to assess the growth-promoting effect of each Streptomyces strain (Horstmann et al 2020).…”

Bacterial Strategies for Improving the Yield, Quality, and Adaptability of Oil Crops

“…Streptomyces sp. CLV45 significantly increased the leguminous crop shoot weight by 36.63% and dry weight by 17.97% due to its high production of IAA and ACC deaminases [101]. In summary, PGPB produce ACC deaminases, which are typically used to eliminate excess ET produced by the host plants under stress conditions.…”

An update about plant growth promoting Streptomyces species

“…Cicer arietinum (chickpea) 23-37% increase in plant organs biomass [69] Streptomyces roseocinereus MS1B15 Hordeum vulgare (barley) 1.5% increase in shoot biomass [70] Streptomyces shenzhenesis TKSC3 Oryza sativa (rice) 33% increase in dry mass [71] Streptomyces albus Panicum miliaceum (millet) 9-12% increase in plant yield [72] Streptomyces globisporus Gossypium herbaceum (cotton) 62% increase in shoot biomass [73] Streptomyces spp. CLV45 Glycine max (soybean) 37% increase in shoot growth [74] Streptomyces hydrogenans DH16 Pisum sativum (pea) 39.45-58.04% increase recorded for numerous growth parameters [11] Streptomyces spp. JR9 Oryza sativa (rice) 18% increase in shoot biomass [75] Streptomyces alfalfae Panicum virgatum (switchgrass) 50% increase in shoot biomass [76] in the future.…”