Characterization of plant growth-promoting bacteria associated with avocado trees (Persea americana Miller) and their potential use in the biocontrol of Scirtothrips perseae (avocado thrips)

Abstract

Plants interact with a great variety of microorganisms that inhabit the rhizosphere or the epiphytic and endophytic phyllosphere and that play critical roles in plant growth as well as the biocontrol of phytopathogens and insect pests. Avocado fruit damage caused by the thrips species Scirtothrips perseae leads to economic losses of 12-51% in many countries. In this study, a screening of bacteria associated with the rhizosphere or endophytic phyllosphere of avocado roots was performed to identify bacterial isolates with plant growth-promoting activity in vitro assays with Arabidopsis seedlings and to assess the biocontrol activity of the isolates against Scirtothrips perseae. The isolates with beneficial, pathogenic and/or neutral effects on Arabidopsis seedlings were identified. The plant growth-promoting bacteria were clustered in two different groups (G1 and G3B) based on their effects on root architecture and auxin responses, particularly bacteria of the Pseudomonas genus (MRf4-2, MRf4-4 and TRf2-7) and one Serratia sp. (TS3-6). Twenty strains were selected based on their plant growth promotion characteristics to evaluate their potential as thrips biocontrol agents. Analyzing the biocontrol activity of S. perseae, it was identified that Chryseobacterium sp. shows an entomopathogenic effect on avocado thrips survival. Through the metabolic profiling of compounds produced by bacteria with plant growth promotion activity, bioactive cyclodipeptides (CDPs) that could be responsible for the plant growth-promoting activity in Arabidopsis were identified in Pseudomonas, Serratia and Stenotrophomonas. This study unravels the diversity of bacteria from the avocado rhizosphere and highlights the potential of a unique isolate to achieve the biocontrol of S. perseae.

Influence of Sunlight Incidence and Fruit Chemical Features on Oviposition Site Selection in Mango by Anastrepha obliqua: Implications for Management

“…Metabolomic studies based on accurate mass spectrometry represent a powerful tool that has been used to gain insights into more efficient management approaches against notorious plant pests and diseases, such as thrips [80], foraging ants [81] and fusarium wilt [82][83][84]. The untargeted metabolomics study we performed reinforces the idea that A. obliqua females can sense fruit chemical quality, as reported for D. melanogaster [79], since we identified biochemical differences between oviposited and non-oviposited sites in "Criollo" mangos (Figures 4b and 5).…”

Efecto de Bacillus amyloliquefaciens y Pseudomonas migulae sobre el crecimiento de plántulas de uchuva (Physalis peruviana L.) en semillero

“…Los resultados obtenidos en el presente estudio demostraron que la aplicación de B. amyloliquefaciens Bs006 incrementó la longitud de la planta relacionado con tallo y raíz, la biomasa total y el área foliar (Cuadro 1), variables importantes en la calidad del material vegetal, con un aumento de 0,248 g en el peso seco aéreo y de 0,066 g en peso seco de la raíz de plántulas de uchuva, en comparación con el control convencional sin aplicación de microorganismos benéficos. El género Bacillus ha mostrado su alta capacidad de promoción del crecimiento vegetal en múltiples sistemas vegetales (Olanrewaju et al, 2017;Tiing Lau et al, 2020;Tzec-Interián et al, 2020). Los resultados obtenidos en el presente trabajo fueron similares a los reportados por Xu et al (2019), quienes demostraron que Bacillus sp.…”

“…Estas bacterias pueden promover el crecimiento de las plantas, ya sea de forma directa mediante la fijación de nitrógeno, la solubilización de fósforo, potasio y zinc, por la producción de sideróforos y fitohormonas como ácido indolacético, ácidos giberélicos y citoquininas, o indirecta a través de la producción de sustancias antagonistas, como la producción de antibióticos y enzimas líticas (Deketelaere et al, 2017;Glick, 2012;Olanrewaju et al, 2017;Tilak et al, 2005). Estas características han contribuido al éxito de bioproductos basados en estas especies, no solo por su capacidad para promover el crecimiento de las plantas, sino también para reducir el uso de fertilizantes químicos y contribuir a la sanidad de los agroecosistemas (Olanrewaju et al, 2017;Tiing Lau et al, 2020;Tzec-Interián et al, 2020).…”

Advances in Understanding Defense Mechanisms in Persea americana Against Phytophthora cinnamomi

“…Pseudomonas genus and Serratia sp. isolated from the avocado rhizosphere – which produce bioactive cyclodipeptides – were shown to promote root growth in A. thaliana ( Tzec-Interián et al, 2020 ). These microbes could potentially be utilized to help avocado rootstocks overcome the root growth restricting effects of P. cinnamomi .…”