Os11g0559200
The rice Os11g0559200 was recongized as OsXa21 in 1990s. However, the related research of this gene can date back to the year 1977, when Indian Plant Pathologist Dr. S. Devadath found a strain of Oryza barthii from Manila is resistant to all the races of bacterial blight[1].
Contents
Annotated Information
Figure 1. Graphical representation of the chromosome of Xanthomonas oryzae pv. oryzae(from reference[2]).
Function
Bacterial blight is the most destructive bacterial disease of rice distributed all over the world, especiallyin Asia and Africa. OsXa21 is the first disease resistance gene cloned from rice, which encodes a receptor-like kinase and confers broad spectrum resistance against Xanthomonas oryzae pv. oryzae ( Xoo ). As a member of pattern recognition receptors (PRRs), OsXa21 plays an imortant role in pathogen-associated molecular patterns (PAMPs). It is a resistance gene in plants which is critical to the activation of innate immune response.
- Xa21 encodes a receptor-like kinase, which has 3 parts: a receptor-like kinase (RLK) with leucine-rich repeats (LRR) in the presumed extracellular domain, a transmembrane domain and a serine–threonine protein kinase domain[3], the last two part are the most important, because they have correlation with the resistance of Xa21. And this disease resistance gene is a member of a multigene family which has seven family members. Xa21D, an Xa21 gene family member, encodes a predicted protein consisting of a signal peptide and a LRR domain, which is highly similar to the LRR domain of XA21. RLKs play important roles in many biological processes, including development and growth, in both animals and plants[4]. In the Xa21 gene family, LRRs of different members may have evolved to recognize different pathovars and may confer altered resistance phenotypes.
- In 1992, Ronald located Xa21 on chromosome11[5]. Based on the frequency with which they discovered polymorphic Xa21-1inked markers, they estimate the size of the introgressed region containing Xa21 to be approximately 800 kb[6].
GO assignment(s): GO:0004672, GO:0004674, GO:0005524, GO:0006468
Expression
- The expression analysis made by Chang-Jin Park1 et al. in 2010 showed that Xoo infection could induce the expression of OsXa21, then regulates XA21-mediated immune response (Figure 2). They further found that the constitutive expression of OsXa21 could enhance resistance to Xoo and the overexpression of OsXa21 up-regulate a new set of defense-related genes[7].
Figure 2. The expression pattern of OsXa21 after infected by Xoo(from reference[7]).
- Thus, they conclude that altering the regulation of OsXa21 could be used for enhancing resistance to Xoo at multiple developmental stages[7].
Evolution
- Synteny and phylogenetic analysis showed that frequent gene translocation, duplication and/or loss, have occurred at Xa21 homologous loci, suggesting that they have undergone or are undergoing rapid generation of copy number variations. Many researchers have domenstated that during the evolution of the Xa21 gene family, it’s common to find gene duplication and diversification and they think these processes may associated with the creation of novel resistance phenotypes[4].
- The study by Yang J et al. showed that Xa21 gene in different generation and genetic background could be stably inherited and presented sustained resistance to RBB and no re-sistance decline or loss were found in successive planting for 16 generations[8].
Conserved Domains
Labs working on this gene
- Department of Plant Pathology and the Genome Center, University of California Davis, Davis, California 95616, USA.
- Center for Engineering Plants for Resistance against Pathogens, University of California, Davis, California 9561 6
- Department of Plant Molecular Systems Biotechnology, Crop Biotech Institute, Kyung Hee University, Yongin 446-701, Korea.
- Department of Molecular Microbiology, School of Medicine, Washington University, St. Louis, MO 63110, USA.
- State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210093, China
- Genetic Diversity Department, National Institute of Agrobiological Sciences (Tsukuba, Ibaraki 305–8602, Japan)
- Graduate School of Biotechnology & Crop Biotech Institute, Kyung Hee University, Yongin 446-701, South Korea
References
- ↑ KHUSH G S, BACALANGCO E, Ogawa T. 18. A New Gene for Resistance to Bacterial Blight from O. longistaminata. Rice Genet Newslett 1990, 7: 121 ~ 122.
- ↑ Ochiai H, Inoue Y, Takeya M, et al. Genome sequence of Xanthomonas oryzae pv. oryzae suggests contribution of large numbers of effector genes and insertion sequences to its race diversity[J]. Japan Agricultural Research Quarterly, 2005, 39(4): 275.
- ↑ Ronald P C, Albano B, Tabien R, et al. Genetic and physical analysis of the rice bacterial blight disease resistance locus, Xa21[J]. Molecular and General Genetics MGG, 1992, 236(1): 113-120.
- ↑ 4.0 4.1 Tan S, Wang D, Ding J, et al. Adaptive evolution of Xa21 homologs in Gramineae[J]. Genetica, 2011, 139(11-12): 1465-1475.
- ↑ Song W Y, Wang G L, Chen L L, et al. A receptor kinase-like protein encoded by the rice disease resistance gene, Xa21[J]. Science, 1995, 270(5243): 1804-1806.
- ↑ Andaya C B, Ronald P C. A catalytically impaired mutant of the rice Xa21 receptor kinase confers partial resistance to Xanthomonas oryzae pv oryzae[J]. Physiological and molecular plant pathology, 2003, 62(4): 203-208.
- ↑ 7.0 7.1 7.2 Ronald P C, Albano B, Tabien R, et al. Genetic and physical analysis of the rice bacterial blight disease resistance locus, Xa21[J]. Molecular and General Genetics MGG, 1992, 236(1): 113-120.
- ↑ Yang J, Ni D, Wu J. Breeding and food safety evaluation of transgenic hybrid rice harboring Xa21 gene[J]. Molecular Plant Breeding, 2006, 14.
