China 
Africa 
Explore chapters and articles related to this topic
Trichoderma spp. as a Green Technology for the Agri-Food Industry
Published in Abu Zahrim Yaser, Poonam Khullar, A. K. Haghi, Green Materials and Environmental Chemistry, 2021
Stefany Elizabeth Reza-Escandón, Cristóbal Noé Aguilar, Raúl Rodríguez-Herrera, José D. García-García, Anna Iliná, Georgina Michelena-Álvarez, José Luis Martínez-Hernández
Volatile organic compounds (VOCs) are the metabolites that plants and microorganisms release into the air. They are important in intra- and interspecific communication in the rhizosphere [17], being the structure infochemicals as mono- and sesquiterpenes, alcohols, ketones, lactones, esters or C8 compounds that are part of the wealth of the emissions of volatile microbial compounds. Its positive and/or negative effects on other organisms can become useful agricultural tools. It has been shown that these promote the development of plants and their defense system. Thus, in- in vitro tests where the plants of Arabidopsis thaliana exposed to the VVV of T. virens showed an increase in two times of the total fresh weight in comparison with the axenically cultivated seedlings. The stimulation of the branching of lateral roots was observed, thus increasing their capacity to absorb nutrients. The production of jasmonic acid, a phytohormone that occurs when plants interact with potential pathogens or with insects, was demonstrated by activating signaling cascades that increase the plant’s immunity through changes in gene expression. In addition, the production of hydrogen peroxide, an oxygen reactive species that, like jasmonic acid, triggers defense responses were observed. Both help in the control of diseases, as in the case of the test carried out with plants infected with Botrytis cinerea that, when they were exposed to VOCs from two strains of Trichoderma (Tv10.4 and Tv29.8), the symptoms of induced chlorosis and the percentage of dead plants from 80% to 10 and 15% respectively were decreased [18].
Approaches to Enhance Antioxidant Defense in Plants
Published in Hasanuzzaman Mirza, Nahar Kamrun, Fujita Masayuki, Oku Hirosuke, Tofazzal M. Islam, Approaches for Enhancing Abiotic Stress Tolerance in Plants, 2019
Hamid Mohammadi, Saeid Hazrati, Mohsen Janmohammadi
Jasmonic acid and its related compounds regulate the defensive responses of plants to stress conditions, including infections of pathogens, osmotic stress (Rao et al., 2000; Devoto and Turner, 2005), and heavy metal stress (Maksymiec et al., 2005). Studies have shown that JA is effective in regulating defensive responses by activating the secondary messengers, including H2O2 (Orozco-Cárdenas et al., 2001). Also, the expression of responsive genes to JA, including antioxidants and defense-related proteins (such as enzyme-encoding genes involved in the synthesis of ascorbate and glutathione), is increased under stress conditions (Xiang and Oliver, 1998; Wolucka et al., 2005; Shan and Liang, 2010).
Bacterial Synthesis of Metallic Nanoparticles
Published in Ramesh Raliya, Nanoscale Engineering in Agricultural Management, 2019
Shweta Agrawal, Mrinal Kuchlan, Jitendra Panwar, Mahaveer Sharma
Intuitively, nanoparticles can be used as biomarkers or as a rapid diagnostic tool for detection of bacterial, viral and fungal plant pathogens. Researchers have used nano-gold based immuno-sensors that could detect Karnal bunt (Tilletia indica) disease in wheat using surface plasmon resonance (SPR). Additionally, plants respond to different stress conditions through physiological changes such as induction of systemic defence, probably regulated by plant hormones: Jasmonic acid, methyl jasmonate and salicylic acid. This indirect stimulus was successfully harnessed in order to develop a sensitive electrochemical sensor, using modified gold electrode with copper nanoparticles, to monitor the levels of salicylic acid in the oil seeds to detect the fungi (Sclerotinia sclerotiorum). Researches on similar sensors and sensing techniques needs to be expanded for detecting pathogens, their by-products, or monitor physiological changes in plants and then apply pesticides and fertilizers as needed prior to the onset of symptoms (Khot et al. 2012). A mixture of titanium dioxide, aluminium and silica was reported to effectively control downy and powdery mildew of grapes, probably through direct action on the hyphae, interference with fungal mechanism of recognition of plant surface and stimulation of plant physiological defences. A new composition of nano-silver combined with silica molecules and water-soluble polymer proved effective in suppressing the growth of many plant pathogenic fungi and bacteria. Pythium ultimum, Magnaporthe grisea, Colletotrichum gloeosporioides, Botrytis cinere and Rhyzoctonia solani showed 100% inhibition of growth at 10 ppm concentration; whilst, Bacillus subtilis, Azotobacter chrococuum, Rhizobium tropici, Pseudomonas syringae, Xanthomonas compestris pv. and Vesicatoria showed 100% growth inhibition at 100 ppm concentration of the nanosized silica-silver (Sharon et al. 2010, Mishra and Singh 2014).
Heavy metal (loid)s phytotoxicity in crops and its mitigation through seed priming technology
Published in International Journal of Phytoremediation, 2023
Rajesh Kumar Singhal, Mahesh Kumar, Bandana Bose, Sananda Mondal, Sudhakar Srivastava, Om Parkash Dhankher, Rudra Deo Tripathi
Jasmonic acid (JA) has a regulatory role in plant growth, development, and stress protection. JA and its active derivatives (jasmonates) modulate a range of defense responses against various stresses (Wasternack 2007). Sharma et al. (2013) discussed the role of JA on photosynthetic pigments and stress markers in pigeon pea seedlings under Cu stress. Sirhindi et al. (2016) noted that Ni toxicity modulates the seedling’s shoot and root weights, chlorophyll content, metabolite, and antioxidant enzymes gene expression in soybean, which could be alleviated by using JA as seed primer. Furthermore, Mir, Sirhindi et al. (2018) depicted the role of JA seed priming in improving growth attributes under Ni toxicity in the soybean. They found that JA improved the antioxidant enzyme, redox status, ROS, and regulated the uptake of Ni. Recently, reported that JA priming declines levels of MDA, O2•−, and H2O2, and decreases membrane and nuclear damage in tomatoes. They also found that RBO (Rubredoxin oxidoreductase) and P-type ATPases transporter genes under Pb stress, which reduce the translocation of Pb in the seedlings. Moreover, JA seed priming improves the photosynthetic activity, ascorbate-glutathione pathway, secondary metabolite, and enhances osmolytes and metal chelating compounds production under Pb stress (Bali, Jamwal, Kaur, et al. 2019; Bali, Jamwal, Kohli, et al. 2019).