Understanding the variability of rice bacterial blight pathogen, Xanthomonas oryzae pv. oryzae in Andhra Pradesh, India.

Bacterial blight (BB) of rice is a devastating disease caused by Xanthomonas oryzae pv. oryzae (Xoo). The evolution of new pathogenic races of bacterial blight pathogen is always a potential threat for rice production. The deployment of pathotype-specific resistant genes in the host plants is a feasible strategy to develop BB-resistant varieties. Therefore, continuous disease monitoring, identification of Xoo pathotypes, and their distribution are crucial to managing BB. In this study, 71 Xoo isolates were collected from the Godavari delta in Andhra Pradesh (India) and their virulence profiles on rice BB differentials were characterized. Data revealed that different International Rice Bacterial Blight (IRBB) lines with single BB resistance genes were susceptible to 73.2%-97.2% of the isolates, except IRBB13 (possessing BB resistance gene, xa13) which showed a moderately susceptible or susceptible reaction to 47.9% of the isolates. Three gene combination rice differentials like IRBB56 (Xa4 + xa5 + xa13), IRBB57 (Xa4 + xa5 + Xa21), IRBB58 (Xa4 + xa13 + Xa21), and IRBB59 (xa5 + xa13 + Xa21) showed very broad-spectrum resistance to majority of the Xoo isolates from the region. None of the tested Xoo isolates were virulent on IRBB58 (Xa4 + xa13 + Xa21), IRBB60 (Xa4 + xa5 + xa13 + Xa21), and IRBB66 (Xa4 + xa5 + Xa7 + xa13 + Xa21). Based on the virulence reaction, 71 Xoo isolates were grouped into 10 major pathotypes. Highly virulent pathotypes viz., IXoPt # 14, 17, 19, and 22 can break the resistance of major BB-resistant genes and were commonly distributed throughout the surveyed regions. Genotypic data of 71 Xoo isolates using J3 primer divided them into three major clusters. Cluster I consisted of 24 Xoo isolates that belonged to pathotype IXoPt-19. Cluster II consisted of 41 Xoo isolates belonging to seven different pathotypes, and Cluster III was composed of six isolates from three different pathotypes. The findings of this study will be helpful to develop rice varieties with pathotype-specific broad-spectrum resistance against BB.

CuO assisted borate 1393B3 glass scaffold with enhanced mechanical performance and cytocompatibility: An In vitro study.

Herein, three dimensional porous 1393B3 borate-based glass (BBG) scaffold along with their CuO derivatives (C1BBG, C2BBG, and C3BBG) tailored with trabecular bones' architecture were prepared by melt-quench route followed by foam replica technique. The properties of 'CuO incorporated' scaffolds, as compared to 'as prepared' scaffold were analyzed by a series of In vitro investigations for enhancement in biological compatibility, bioactivity, and physicomechanical performances. The in vitro study demonstrates superior mechanochemical stability of CBBGs (CuO derived 1393B3) than the pure BBG, while causing no or minimal effect on bioactivity and cytocompatibility post CuO incorporation to the BBG. In fact, the biological compatibility examined through MTT, Live/Dead, and cell adhesion study using the L929 cell lines was enhanced in the CBBGs up to 1% CuO incorporated scaffolds (C1BBG and C2BBG) in most cases. However, the enhanced biological compatibility was observed in C1BBG in comparison to other BBGs. Thus, the CuO incorporation into BBG enhanced mechanochemical and biological performance without affecting the bioactivity of the scaffold; henceforth, CBBGs could be considered neo bone tissue regenerative biomaterials.

Studies on effect of CuO addition on mechanical properties and in vitro cytocompatibility in 1393 bioactive glass scaffold.

Copper doped bioactive glasses have been reported as the potential biomaterial for diseased or damaged bone repair and act as stimulants to new bones formation. In the present manuscript, we have synthesized 1393 derived glass based scaffold with the general formula of (54.6 - X)SiO2·6Na2O·7.9 K2O·7.7 MgO·22 CaO·1.74 P2O5·XCuO (all are in mole%; where X = 0,1,2,3) through traditional melt-quench route and the samples were designated as 1393, 1393-1Cu, 1393-2Cu and 1393-3Cu respectively. Polymer foam with interconnected pores has been used on later stage to prepare porous (porosity > 50%) bioactive scaffolds. The addition of CuO in glass scaffolds was to ensure its cytocompatibility, ability to enhance cell proliferation and improvements in mechanical properties. Increasing trend of CuO in the 1393 glass scaffold has resulted in increasing compressive and flexural strength and elastic modulus of the scaffolds. In-vitro cellular growth inhibition and cell viability assay of CuO incorporated 1393 glass scaffolds demonstrated that it did not inhibit proliferation and viability of human squamous carcinoma cell (SCC-25) at low materials concentration. The materials caused moderate level of apoptosis at higher concentrations and were also tolerated by human RBC as studied by hemolytic assay. The results indicated that CuO incorporated 1393 scaffolds could be a potential biomaterial for neobone tissue engineering application.