Molecular interaction between plants and Trichoderma species against soil-borne plant pathogens.

Trichoderma spp. (Hypocreales) are used worldwide as a lucrative biocontrol agent. The interactions of Trichoderma spp. with host plants and pathogens at a molecular level are important in understanding the various mechanisms adopted by the fungus to attain a close relationship with their plant host through superior antifungal/antimicrobial activity. When working in synchrony, mycoparasitism, antibiosis, competition, and the induction of a systemic acquired resistance (SAR)-like response are considered key factors in deciding the biocontrol potential of Trichoderma. Sucrose-rich root exudates of the host plant attract Trichoderma. The soluble secretome of Trichoderma plays a significant role in attachment to and penetration and colonization of plant roots, as well as modulating the mycoparasitic and antibiosis activity of Trichoderma. This review aims to gather information on how Trichoderma interacts with host plants and its role as a biocontrol agent of soil-borne phytopathogens, and to give a comprehensive account of the diverse molecular aspects of this interaction.

Nanomaterials in photocatalysed organic transformations: development, prospects and challenges.

Photoredox catalysis has gained widespread attention in recent years as a powerful tool to drive chemical transformations in the presence of light, particularly for molecules that are capable of showing redox activity. A typical photocatalytic pathway may involve electron or energy transfer processes. To date, photoredox catalysis has been explored mainly with Ru, Ir and other metal or small molecule based photocatalysts. Due to their homogeneous nature, they cannot be reused and are not economical. These factors have motivated researchers to look for an alternate class of photocatalysts which are more economical and reusable, thus paving the way for protocols that can be easily transferred to the industrial sectors as well. In this regard, scientists have come up with various nanomaterials as sustainable and economical alternatives. These have unique properties that arise from their structure, surface functionalization, etc. Apart from that, at the lower dimensions, they bear an increased surface to volume ratio, which can provide an enhanced number of active sites for catalysis. Nanomaterials have been used for various applications like sensing, bioimaging, drug delivery, energy generation, etc. However, their potential as photocatalysts for organic transformations has been taken up as a subject of research quite recently. This article focusses on the use of nanomaterials in photo-mediated organic transformations with a wider goal to motivate readers from materials as well as organic synthetic backgrounds to dig deeper into this area of research. Various reports have been included to cover the plethora of reactions that have been explored with nanomaterials as a photocatalyst. The scientific community has also been introduced to the challenges and prospects of the field, which will further help in its growth. In a nutshell, this writeup will help to cater to the interest of a large group of researchers to highlight the prospects of nanomaterials in photocatalysis.

Nanotechnological approaches for management of soil-borne plant pathogens.

Soil borne pathogens are significant contributor of plant yield loss globally. The constraints in early diagnosis, wide host range, longer persistence in soil makes their management cumbersome and difficult. Therefore, it is crucial to devise innovative and effective management strategy to combat the losses caused by soil borne diseases. The use of chemical pesticides is the mainstay of current plant disease management practices that potentially cause ecological imbalance. Nanotechnology presents a suitable alternative to overcome the challenges associated with diagnosis and management of soil-borne plant pathogens. This review explores the use of nanotechnology for the management of soil-borne diseases using a variety of strategies, such as nanoparticles acting as a protectant, as carriers of actives like pesticides, fertilizers, antimicrobials, and microbes or by promoting plant growth and development. Nanotechnology can also be used for precise and accurate detection of soil-borne pathogens for devising efficient management strategy. The unique physico-chemical properties of nanoparticles allow greater penetration and interaction with biological membrane thereby increasing its efficacy and releasability. However, the nanoscience specifically agricultural nanotechnology is still in its toddler stage and to realize its full potential, extensive field trials, utilization of pest crop host system and toxicological studies are essential to tackle the fundamental queries associated with development of commercial nano-formulations.

Destructive Phytophthora on orchids: current knowledge and future perspectives.

Anton de Bary first coined the genus, Phytophthora, which means "plant destroyer", viewing its devastating nature on potatoes. Globally plants have faced enormous threat from Phytophthora since its occurrence. In fact, a century ago, Phytophthorapalmivora was first reported on Dendrobium maccarthiae in Sri Lanka. Since then, members of beautiful flowering crops of the family Orchidaceae facing the destructive threat of Phytophthora. Several Phytophthora species have been recorded to infect orchids with economic loss worldwide. To date, orchids are attacked by 12 species of Phytophthora. Five Phytophthora species (P. palmivora, P. nicotianae, P. cactorum, P. multivesiculata, P. meadii) are the major pathogenic Oomycetous Chromista" rather than true fungi frequently occurred on Orchidaceae. Phytophthora palmivora (having ~32 orchid host genera in 15 countries), Phytophthora nicotianae (having ~15 orchid host genera in 16 countries), Phytophthora cactorum (having ~43 orchid host genera in 6 countries), Phytophthora multivesiculata (having 2 orchid host genera in 5 countries) and Phytophthora capsici (having 2 orchid host genera in all Vanilla growing countries) are potential destroyers of Orchidaceae. Most of them are water loving Oomycetes cause disease in moist environments (> 80% RH) at 16-28°C. In artificially constructed orchidaria, anthropogenic factors are mostly contributed to the dissemination Phytophthora diseases in addition to many other factors. Water management, clean cultivation, and agro-chemicals are the major options for effective management of orchid Phytophthora, as the eco-friendly management options like development of resistant hybrids/cultivars, biological disease management, transgenic approaches, RNAi technology remained in the infant stage. In this review, we intended to highlight the insight of Phytophthora diseases associated with the orchid disease with reference to the historical aspect of the diseases, symptoms and signs, the pathogens, taxonomy, geographic distribution, host range within the Orchidaceae, pathogen identification, molecular diagnostics, mating types and races, management options and strategies and future perspectives.

Advances in Nanotechnology as a Potential Alternative for Plant Viral Disease Management.

Plant viruses cause enormous losses in agricultural production accounting for about 47% of the total overall crop losses caused by plant pathogens. More than 50% of the emerging plant diseases are reported to be caused by viruses, which are inevitable or unmanageable. Therefore, it is essential to devise novel and effective management strategies to combat the losses caused by the plant virus in economically important crops. Nanotechnology presents a new tendency against the increasing challenges in the diagnosis and management of plant viruses as well as plant health. The application of nanotechnology in plant virology, known as nanophytovirology, includes disease diagnostics, drug delivery, genetic transformation, therapeutants, plant defense induction, and bio-stimulation; however, it is still in the nascent stage. The unique physicochemical properties of particles in the nanoscale allow greater interaction and it may knock out the virus particles. Thus, it opens up a novel arena for the management of plant viral diseases. The main objective of this review is to focus on the mounting collection of tools and techniques involved in the viral disease diagnosis and management and to elucidate their mode of action along with toxicological concerns.