Meta-analysis of common wheat physiological response to biotic stresses

Common wheat (Triticum aestivum L.), like other plants, has evolved a variety of ways to resist pathogens. However, there are some studies that reported different results at the phenotypic and physiological levels. Therefore, this meta-analysis was conducted to reveal common trends, address some controversy, and a source of heterogeneity in 19 wheat phenotypic indices. It was found that the overall response is a reduction in thousand kernel weight (TKW), kernel number, plant biomass, grain yield, relative water content (RWC), soil and plant analysis development (SPAD), and proline, and an increase in ascorbate peroxidase (APX), catalase (CAT), glutathione-S-transferase (GST), hydrogen peroxide (H2O2), malondialdehyde (MDA), peroxidase (PDX), polyphenol oxidase (PPO), superoxide dismutase (SOD), flavonoids, putrescine (PUT), salicylic acid (SA), and spermidine (SPD). However, the model was not significant for TKW, H2O2, PUT, SA, and SPD (p >= 0.05). The moderator analysis revealed that the effect of "cultivar" was significant on the kernel number (p <= 0.035) and GST (p <= 0.008), and the effect of "type of biotic stress" was significant on the grain yield (p <= 0.001), APX (p <= 0.0001), CAT (p <= 0.0009), PDX (p <= 0.0344), flavonoids (p <= 0.001), and SPAD (p <= 0.0201). For plant biomass, the intercept effect of "cultivar" and "type of biotic stress" was significant (p <= 0.0187). The mixed-effect analysis addressed a source of heterogeneity in studies used in our study. However, to address additional factors affecting these parameters, some consideration for future studies is needed.