Leonor Angélica Guerrero-Zúñiga

Effect of the inoculation of Axonopus affinis plantlets with immobilized rhizobacteria exposed to cadmium

The interactions between plants with rhizosphere and root associated microorganisms have been considered because they are potentially useful in phytoremediation and are used as microbial inoculates (biofertilizers) that give bioprotection to plants against biotic and abiotic stresses. One of the methods safe and effective for introducing bioinoculants is the encapsulation of cells in biodegradable gel matrices like alginate. The aim of this study is to evaluate the effect of three rhizobacteria (

Analysis of the Ectomycorrhizal Enzymatic Functional Diversity of Fagus mexicana

In forest ecosystems, ectomycorrhizal symbiosis is able to produce a large range of extracellular and cell wall-bound enzymes which hydrolyze compounds contained in soil organic matter. Enzymatic activity profiles of individual ectomycorrhiza have value of functional traits to characterize the diversity of ectomycorrhizal (ECM) communities. Fagus mexicana is an endemic and only species that has restricted distribution to cloud forest of Sierra Madre Oriental in México and there are few works focused to the relationship between this forest species and ectomycorrhizal, which enhance its growth and development. This work analyzes the enzyme functional diversity of ectomycorrhizal fungi associated to F. mexicana trees of different ages. In this study, the ECM species: Cantharellus cibarius Fr., Laccaria amethystina Cook, Lactarius subdulcis (Pers.) gray and Xathoconium separans (Peck) Halling & Both, were founded near these trees and the influence of the niche on the mean catabolic activity of ectomycorrhizal community, varied according to the dominant substrate; where L. amethystina and X. separans presented the highest β-glucosidase and acid phosphatase activities in F. mexicana tips. The enzymatic profiles demonstrated a functional plasticity of the ectomycorrhizal species associated to the age of trees tested and also could be a trait of their capability of adaptation to the cloud forest ecosystem.

Plant Physiology Processes Associated with “Plant-Plant Growth-Promoting Rhizobacteria” Bioassays for the Enhanced Heavy Metal Removal

Rhizoremediation considers the phytoextraction and soil bioaugmentation strategies and optimize the synergistic effect between plants and microorganisms with a physiological basis related only to plants. It is known that plant growth-promoting rhizobacteria (PGPR) affect the plants growth facilitating the uptake of nutrients and protecting them; this interaction has been attractive because the biotechnological potential of microorganisms for metal removal from soils and transport of them to the plants. In the following sections of this chapter, the authors give some analysis of the importance about the establishment of “plant-PGPR bioassays” as tools to compare the relationships between in vitro physiological characteristics of rhizobacteria isolated from plant metal accumulators and the plant’s physiology response, as follows: importance of siderophores as plant growth-promoting trait, evaluation of the in vitro production of siderophores by rhizobacteria, utility of the measurement of antioxidant activity in plants as indicator of heavy metal stress, and, finally, the description of cadmium effect by the antioxidant activity in two bioassays, with plant cell cultures and plantlets inoculated with a siderophore-producing bacteria (SPB).