Xa26, a gene conferring resistance to Xanthomonas oryzae pv. oryzae in rice, encodes an LRR receptor kinase‐like protein

Abstract

SummaryRice bacterial blight, caused by Xanthomonas oryzae pv. oryzae (Xoo), is one of the most serious rice diseases worldwide. A rice gene, Xa26, conferring resistance against Xoo at both seedling and adult stages was isolated by map-based cloning strategies from the rice cultivar Minghui 63. Xa26 belongs to a multigene family consisting of four members. It encodes a leucine-rich repeat (LRR) receptor kinase-like protein and is constitutively expressed. Sequence analysis revealed that IRBB3 and Zhachanglong lines that are resistant to a broad range of Xoo strains, also carry Xa26. However, signi®cant difference in lesion length was observed among these lines after inoculation with a set of Xoo strains. Moreover, transgenic plants carrying Xa26 showed enhanced resistance compared with the donor line of the gene in both seedling and adult stages. These results suggest that the resistance conferred by Xa26 is in¯uenced by the genetic background.

Fine mapping, physical mapping and development of diagnostic markers for the Rrs2 scald resistance gene in barley

“…oryzae (Song et al 1995;Sun et al 2004), Pi-d2 of rice against the fungal pathogen Magnaporthe grisea (Chen et al 2006), the Pto gene for race-specific resistance to Pseudomonas syringae in tomato (Martin et al 1993) or the barley Rpg1 gene against Puccinia graminis f. sp. tritici (Brueggeman et al 2002).…”

A CCCH-Type Zinc Finger Nucleic Acid-Binding Protein Quantitatively Confers Resistance against Rice Bacterial Blight Disease

“…The indica rice variety Minghui 63 carries the R gene Xa3/Xa26 for resistance to Xoo strain PXO61, and the japonica variety Mudanjiang 8 is susceptible to PXO61 (Sun et al, 2004). However, Xa3/Xa26 can mediate a higher level and a more broad-spectrum resistance to Xoo in the Mudanjiang 8 background than in the Figure 2.…”

“…Rice variety Zhenshan 97 is susceptible to PXO61 and is an indica variety, as is the moderately resistant Minghui 63 carrying R gene Xa3/ Xa26 . Rb49 is a transgenic line carrying a single copy of Xa3/Xa26 driven by its native promoter, with the genetic background of susceptible rice variety Mudanjiang 8; it is more resistant to Xoo than Minghui 63, the donor of Xa3/Xa26 (Sun et al, 2004;Cao et al, 2007). C3H12 showed a similar expression pattern in both resistant and susceptible rice lines after Xoo infection (Fig.…”

“…Genetic background influences the function of Xa3/ Xa26 in resistance against Xoo; the Mudanjiang 8 background facilitates the function of Xa3/Xa26 more than does the Minghui 63 background (Sun et al, 2004;Cao et al, 2007). The function of Xa3/Xa26 is associated with its expression level: the higher its expression, the more resistant the plant; Xa3/Xa26 has a higher expression level in Mudanjiang 8 than in Minghui 63 .…”

“…Disease was scored by measuring the percentage lesion area (lesion length/leaf length) at 2 weeks after inoculation. The bacterial growth rate in rice leaves was determined by counting colony-forming units (Sun et al, 2004).…”