Brassinosteroids Benefit Plants Performance by Augmenting Arbuscular Mycorrhizal Symbiosis

Brassinosteroids (BR) and Arbuscular mycorrhizas (AM) symbiosis play an important role in improving plant growth and development. Previous studies have shown that there is a complex regulatory network between phytohormones and AM symbiosis.

A review of the interaction of medicinal plants and arbuscular mycorrhizal fungi in the rhizosphere

Medicinal plants are well known to have the advantages of high concentration of medicinal ingredients having clinical importance, curative value, small toxic and side effects. Important compounds viz., paclitaxel, camptothecin, and vincristine have been developed from medicinal plants as first-line of clinical drugs, leading to their consistently increasing demand globally. However, the destruction of natural environment due to excessive mining threatened such resources jeopardizing the successful growing of medicinal plants. A group of beneficial arbuscular mycorrhizal (AM) fungi is known to exist in the rhizosphere of medicinal plants, which can establish a reciprocal symbiosis with their roots, namely arbuscular mycorrhizas. These AM fungi are pivotal in the habitat adaptation of medicinal plants. Studies have demonstrated that AM fungi aided in growth promotion and nutrient absorption of medicinal plants, thereby, accelerating the accumulation of medicinal ingredients and aiding resistance against abiotic stresses such as drought, low temperature, and salinity. An AM-like fungus Piriformospora indica is known to be cultured in vitro without roots, later showed analogous effects of AM fungi on medicinal plants. These fungi provide new mechanistic pathways towards the artificial cultivation of medicinal plants loaded with ingredients in huge demand in international market. This review provides an overview of the diversity of AM fungi inhabiting the rhizosphere of medicinal plants, and analyzes the functioning of AM fungi and P. indica, coupled with future lines of research.

Plant herbivore protection by arbuscular mycorrhizas: A role for fungal diversity?

The symbiotic association between arbuscular mycorrhizal (AM) fungi and terrestrial plants can enhance plant defences against insect herbivores. Despite advances in our understanding of how AM fungi affect plant tolerance and resistance based defence mechanisms, we contend that the role of fungal diversity in these interactions continues to be largely overlooked. This is problematic considering plants typically associate with multiple AM fungi in both natural and agriculturally managed environments in a way which varies spatially and temporally. While the importance of mycorrhizal fungal diversity is being increasingly incorporated into research efforts across various facets of ecology, progress on how AM fungal diversity mediates plant protection from herbivory is disparate and piecemeal. Here we discuss why it is important to focus efforts on understanding how AM fungal diversity can shape plant defence outcomes and highlight key knowledge gaps to be addressed.

Quantifying Root Colonization in Arbuscular Mycorrhizas by Image Segmentation and Machine Learning

MotivationArbuscular mycorrhizas are the most widespread plant symbioses and involve the majority of crop plants. The beneficial interaction between plant roots and a group of soil fungi (Glomeromycotina) grants the green host a preferential access to soil mineral nutrients and water, supporting plant health, biomass production and resistance to both abiotic and biotic stresses. The nutritional exchanges at the core of this symbiosis take place inside the living root cells, which are diffusely colonized by specialized fungal structures called arbuscules. For this reason, the vast majority of studies investigating arbuscular mycorrhizas and their applications in agriculture require a precise quantification of the intensity of root colonization. To this aim, several manual methods have been used for decades to estimate the extension of intraradical fungal structures, mostly based on optical microscopy observations and individual assessment of fungal abundance in the root tissues. ResultsHere we propose a novel semi-automated approach to quantify AM colonization based on digital image analysis and compare two methods based on image thresholding and machine learning. Our results indicate in machine learning a very promising tool for accelerating, simplifying and standardizing this critical type of analysis, with a direct potential interest for applicative and basic [email protected]; [email protected]