Phylogenetic, genetic, and phenotypic diversity of Pseudomonas syringae pv. syringae strains isolated from citrus blast and black pit in Tunisia

Abstract

Citrus blast and black pit caused by Pseudomonas syringae pv. syringae (Pss) is the only bacterial disease reported in Tunisian Citrus orchards. The phylogenetic relationship between Pss strains was studied based on multilocus sequence analysis (MLSA), using partial sequences of housekeeping genes rpoD, rpoB, gyrB, cts, and pfk for 14 representative Pss Citrus strains, including the reference strain LMG5496. The MLSA revealed that the studied Tunisian Citrus strains are closely related to LMG5496 and cluster in phylogroup 02. Based on the cts gene, the majority of Citrus strains clustered in clades “a” and “b”. However, five strains were placed in a newly defined clade “g”. We describe the presence of six different type III secreted effectors (T3SEs). These were found with frequencies of 100% for the effector hopAN1 and the helper hrpK1, 65% for hopT1‐2, and 14% for hopN1, hopR1, and hopQ1‐2. Investigation of copper resistance showed that 67% of our Pss Citrus strains from Tunisia are resistant to copper sulphate in vitro, and the copper resistance genes copABCDR were detected in 23% of the strains. Our results present new data concerning the genetic diversity and phylogeny, presence of T3SEs, and copper resistance within the Pss populations that affect Citrus in Tunisia.

Twig black pitting and cankers of pomegranate (Punica granatum) caused by Pseudomonas syringae pv. syringae in Central Italy

“…syringae strains are shown in Figure 3a,b. The four isolates obtained from pomegranate (Figure 3a, lanes 1-4) show the same molecular pattern as CREA-DC 2017 (Figure 3a, lane 5), isolated from Citrus limon in Tunisia (Abdellatif et al, 2020), and CREA-DC 2053 and CREA-DC 2054 (Figure 3a, lanes 8 and 9) isolated from Cicer arietinum, in Italy.…”

“…pv. syringae strains previously isolated from lemon and chickpea in Tunisia and Italy, respectively (Abdellatif et al, 2020). This confirms that the P. syringae population has a quite spread distribution in the world and that the same population can infect different host plants (Morris et al, 2013).…”

Impact of Sedimentary Conditions and Relative Distribution of Sand Sedimentary Minerals in Iraqi Soils

“…The lowest value was in the soil of the Dokan area at the first depth, and the highest was in the Sayed Sadeq area at the second depth, respectively. Electron microscope examinations of Figure (1) showed that the mineral was glassy and sometimes hazy, with black spots on the surface. The mineral was characterized by the presence of two shapes (Sub -Rounded to Sub -angular), and it has clear cracks in two orthogonal directions, giving it the orthogonal structure (Quadrille Structure), and this is what distinguishes it from the orthoclean metal [24].…”

“…Minerals constitute about 90% of the volume of solid particles of mineral soils [1] . Sand minerals are one of the natural resources found in the earth's crust, which result from the different weathering processes of rocks, whether metamorphic, sedimentary, or igneous.…”

Pseudomonas syringae pv. syringae as the new causal agent of cabbage leaf blight

“…P. syringae is most important species of Pseudomonas genus belonging to the class Gammaproteobacteria (Dillon et al., 2019; Kennelly et al., 2007). This bacterium causes diseases and disorders on a vast range of plants over 200 species, including important agricultural products (Abdellatif et al., 2020; Ruinelli et al., 2019). The phylogenetic taxonomy of P. syringae has revised dramatically during of past studies (Marcelletti & Scortichini, 2014; Young, 2010).…”