Citrus Canker

Abstract

Citrus canker is a bacterial disease that severely affects citrus production throughout the world. Xanthomonas spp. are the causal agents of the disease, which manifests as necrotic pustule-like lesions on the plant organs including leaves, fruits and stems. MicroRNAs (miRNAs) are well-established post-transcriptional gene expression regulators that modulate plant responses during many stress circumstances. Accordingly, some bacteria-responsive miRNAs have been shown to have regulatory functions in the plant-pathogen interaction. Due to their small size and conserved structure of miRNAs, stem-loop RT-PCR can be employed to monitor the expression profiles of miRNAs in non-model organisms. In this study, we successfully assessed the

Conclusively, it has been shown that citrus fruits are abundant in macronutrients and are also noticed as source of many micronutrients which are essential for maintaining human health and normal growth (Rouseff and Nagy 1994; Economos and Clay 1999). Among the commercial citrus fruits, lemon (citrus×limon) is considered as one of the most important horticultural products worldwide (USDA 2013). The horticultural yield and fruit quality of lemon trees are frequently influenced by a wide range of biotic stresses. Among them, Xanthomonas citri subsp citir strain A (Xc) causing citrus canker disease with a broad host range is the most destructive threat to lemon production (Brunings and Gabriel 2003). Citrus canker disease is characterized by using symptoms such as water-soaked eruptions, circular and pustule-like lesions which will appear on all plant tissues (Brunings and Gabriel 2003). It seems that the lesions are resulted from changes in cell enlargement (hypertrophy) and cell division (hyperplasia) (Schubert et al. 2001; Brunings and Gabriel 2003; Lin et al. 2009). In spite of the lesions, Xanthomonas fuscans subsp. aurantifolii strain C (XaC) is able to induce hypersensitive response (HR) in lemon tissues (Brunings and Gabriel