Reference "Haplotype diversity at the Pi-ta locus in cultivated rice and its wild relatives"

Reference ID

54737

Title

Haplotype diversity at the Pi-ta locus in cultivated rice and its wild relatives

Source

Phytopathology, 2008, vol. 98, pp. 1305-1311

Authors (4)

Wang-X	Jia-Y
Shu-Q-Y	Wu-D

Abstract

The Pi-ta gene in rice confers resistance to races of Magnaporthe oryzae that
contain AVR-Pita. Pi-ta encodes a predicted cytoplasmic receptor protein with a
nucleotide-binding site and a leucine-rich domain. A panel of 51 Oryza
accessions of AA genome species Oryza sativa, O. glaberrima, O. rufipogon, O.
nivara, and O. barthii, and CC genome species O. officinalis were sequenced to
investigate the diversity present in the exon and intron regions of the Pi-ta
gene. Two major clades were identified, consisting of 16 different sequences
with numerous insertion and deletions. Only one Pi-ta resistance allele was
identified despite DNA sequences revealing 16 Pi-ta variants. Most differences
were identified in the intron region, and obvious selection of any motif was not
observed in the coding region of Pi-ta variants. Reverse-transcription
polymerase chain reaction analysis of seedlings revealed that all Pi-ta variants
were expressed with or without pathogen inoculation. The 15 Pi-ta variants can
be translated into nine proteins highly similar to the Pi-ta protein. Resistance
to M. oryzae expressing AVR-Pita correlates with alanine and susceptibility
correlates with serine at position 918 of Pi-ta in most accessions examined.
These data confirm that a single amino acid controlling resistance specificity
underlies the evolution of resistance of Pi-ta genes in rice.