This study exhausts bioinformatics tools to acquire the entire multi-domain rice Xa21 protein structure and analyzes its interactions with its PAMP RaxX21-sY and co-receptor OsSERK2.

Like animals, plants customarily utilize cell surface-localized receptors to keep track of environmental stimuli, specifically by plasma membrane-associated receptor-like kinases (RLKs). In comparison to other organisms, plants own a variety of RLKs, which insinuates that ligand-receptor-facilitated molecular mechanisms regulate an array of processes during plant development. Here, we take up Arabidopsis receptor-like kinase 7 (RLK7), which shares the archetypal structure of transmembrane receptor kinases accompanied by a receptor-like ectodomain comprising of leucine-rich repeats (LRRs) along with a functional intracellular kinase domain. Interestingly, this distinctive receptor-like kinase not only orchestrates crucial steps during plant development, including the regulation of seed longevity, dormancy, and seed germination speed, but also plays a role in oxidative stress tolerance, salt stress tolerance, and pattern-triggered immunity. This review deciphers the sequence and structure and evaluates existing knowledge of the function and expression pattern of RLK7.

In plant associated pattern-triggered immunity (PTI), pattern-recognition receptors (PRRs) play crucial role in the mechanism of first line of defense against pathogenic invasion. Throughout the event, PRR binds with microorganism's pathogen-associated molecular pattern (PAMP) and recruit co-receptor protein to initiate the primary defense signal. Although several plant PRRs have been identified, very few of them have been fully characterized and studied so far. PRR Xa21 perceives PAMP RaxX21 and activates pattern triggered immunity in Oryzae spp (rice). The early events regulated by Xa21 is mainly binding of it with PAMP RaxX21 as well as recruit a co-receptor protein OsSerk2. This review article elucidates the steps of activating first line of defense mechanism of rice plant arbitrated by PRR Xa21.

Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae is a devastating disease of rice, the staple food crop of Bangladesh. Under field condition the disease significantly damages the phenotypic characteristics of the plants affecting the yield. An assessment of the phenotypic variations due to the disease in 10 rice lines and 17 rice varieties were studied at the maximum tillering stage in both natural and induced epiphytotic conditions. Along with the indigenous cultivars the test materials including the check resistant and susceptible cultivars were collected from IRRI. Significant differences in both plant height and the number of effective tillers were recorded in the check and inoculated lines and varieties. Among the rice lines, RC222 resulted the maximum reduction in plant height (3.18%) in the inoculated plants whereas RC217 yielded the minimum reduction of 1.27%. Among the rice varieties, Binadhan-8 and Binadhan-10 showed the maximum reduction in plant height (11.43% and 18.22% respectively) for the inoculated plants where IRBB21, IRBB65 and Kumragur resulted 0% reduction. The number of effective tiller among the rice lines, RC251 yielded the maximum reduction of 26.19% in the inoculated plants whereas RC192 showed as minimum as 4.16% reduction. For rice varieties, Binadhan-8, Binadhan-10 and BR-11 yielded the maximum reduction of 52.62%, 50.07% and 50.06% while IRBB21, IRBB65 and Kumragur showed 0 % reduction. The findings of such phenotypic variations may contribute significantly to the selection of best lines and further research to develop the disease free commercial varieties of rice against the disease.