Plant Pathology Science

Plants are usually attacked by several pathogens. Different defense pathways in plants have evolved in reaction to pathogens. Plant defense responses have been shown to be regulated by various plant hormones. Brassinosteroids are plant-specific steroid hormones that play important roles in regulating growth and developmental processes. In addition to acting as a regulator of plant growth, they also play a role in defense responses to pathogens. Many researches have been done on their role in plant resistance to fungi, bacteria and viruses, which are described in this article. Further understanding of the role of these hormones in plant defense responses can be useful in inducing resistance or producing plants resistant to pathogens.

Plant viruses cause major losses to agricultural crops worldwide. Plants react to the virus infections via several defense mechanisms, such as ubiquitination. Ubiquitin (Ub) and ubiquitin proteasome system (UPS) play key role in the function modification and degradation of proteins in plants. Ub attachment to the cellular proteins alters the stability, the cellular establishment or activity of the target protein. The key role of UPS has been revealed in defense mechanisms and other plant processes. Viruses as obligate intracellular parasites have evolved mechanisms to interfere UPS. In some cases, it has been shown that viral proteins were targeted by this system. Ubiquitination plays an important role in plant–virus interaction which can lead to plant resistance or pathogenicity in the host plant. Therefore, further understanding of UPS and its role in plant-virus interaction can develop novel methods to increase resistance to viral infections in plants.

Introduction: Blight caused by Ascochyta rabiei is the most destructive disease of chickpea worldwide. Identification of agronomic and morphological properties of disease-resistant cultivars is necessary to set up a suitable chickpea breeding program. Materials and Methods: Twelve agronomic and morphological properties of 21 resistant, semi-resistant, and susceptible chickpea genotypes were investigated in a field experiment in a randomized complete block design with six replications in one agronomic year in western Iran. Results: All genotypes were divided into three main clusters based on the UPGMA dendrogram. The lowest yielding genotypes were located in cluster II and IDDMAR-2012-32 genotype was susceptible to disease and desi-type in this cluster. The genotypes with the highest yield were placed in cluster III, and the genotype Gebres 419-2 was resistant to the disease and the desi-type in this cluster. Among the Kabuli-type genotypes, ILC482 was included in cluster III as a high-yielding and semi-disease-resistant cultivar, and low-yielding FLIp-02-65C and FLIp-01-164C lines along with disease resistance were included in cluster I. Conclusion: Gebres 419-2 can be crossed with FLIp-02-65C or FLIp-01-164C to produce robust, high-yielding Kabuli chickpea varieties with large seeds.