Comparative Genetics of Nucleotide Binding Site-Leucine Rich Repeat Resistance Gene Homologues in the Genomes of Two Dicotyledons: Tomato and Arabidopsis

Abstract

The presence of a single resistance (R) gene allele can determine plant disease resistance. The protein products of such genes may act as receptors that specifically interact with pathogen-derived factors. Most functionally defined R-genes are of the nucleotide binding site-leucine rich repeat (NBS-LRR) supergene family and are present as large multigene families. The specificity of R-gene interactions together with the robustness of plant-pathogen interactions raises the question of their gene number and diversity in the genome. Genomic sequences from tomato showing significant homology to genes conferring race-specific resistance to pathogens were identified by systematically “scanning” the genome using a variety of primer pairs based on ubiquitous NBS motifs. Over 70 sequences were isolated and 10% are putative pseudogenes. Mapping of the amplified sequences on the tomato genetic map revealed their organization as mixed clusters of R-gene homologues that showed in many cases linkage to genetically characterized tomato resistance loci. Interspecific examination within Lycopersicon showed the existence of a null allele. Consideration of the tomato and potato comparative genetic maps unveiled conserved syntenic positions of R-gene homologues. Phylogenetic clustering of R-gene homologues within tomato and other Solanaceae family members was observed but not with R-gene homologues from Arabidopsis thaliana. Our data indicate remarkably rapid evolution of R-gene homologues during diversification of plant families.

QTL analysis of fruit antioxidants in tomato using Lycopersicon pennellii introgression lines

“…M-82 is a red fruited, determinate, processing-type tomato. The genetic constitutions of the 50 ILs, as well as 26 sublines were described by Pan et al (2000). The sublines were obtained as the product of backcrossing selected introgressed lines with M-82, creating smaller introgressed sections.…”

“…Due to overlapping introgressions, effects observed in only one line of two overlapping segments can be ascribed to the unshared region. The L. pennellii ILs thus subdivide the tomato genome into 107 ''bins'' (Pan et al 2000). Bin locations are referred to by chromosome number followed by letter identifying the bin.…”

Modifying Anthocyanins Biosynthesis in Tomato Hairy Roots: A Test Bed for Plant Resistance to Ionizing Radiation and Antioxidant Properties in Space

“…Solyc06g008760.1.1 (Log 2 Fc = −3.05; tomato Glutaredoxin-C13-like ) has been demonstrated to be upregulated in ripening inhibitor ( rin ) mutants of S. lycopersicum ( Kumar et al, 2016 ). Solyc07g055610.2.1 (Log 2 Fc = −2.05); tomato Resistance protein R1) has been related to resistance to late blight ( Bournival et al, 1989 ) and it has been shown to be linked to proteinase inhibitor I3 upon Fusarium oxysporum infection ( Bournival et al, 1989 ; Pan et al, 2000 ). Solyc01g010480 (Log 2 Fc = −2.2; tomato K+ channel KAT1) was demonstrated to be highly upregulated in low K tolerant tomato genotypes upon potassium deficiency ( Zhao et al, 2018 ).…”