Ptr1 evolved convergently with RPS2 and Mr5 to mediate recognition of AvrRpt2 in diverse solanaceous species

Mazo-Molina, D. C.; Mainiero, S.; Haefner, B. J.; Bednarek, R.; Zhang, J.; Feder, A.; Shi, K.; Strickler, S.; Martin, G. B.

doi:10.1101/2020.03.05.979484

Home/Archive/bioRxiv

bioRxiv · 10.1101/2020.03.05.979484

Ptr1 evolved convergently with RPS2 and Mr5 to mediate recognition of AvrRpt2 in diverse solanaceous species

Mazo-Molina, D. C.·Mainiero, S.·Haefner, B. J.·Bednarek, R.·Zhang, J.·Feder, A.·Shi, K.·Strickler, S.·Martin, G. B.

View original source ↗Export metadata ↓

Abstract

The Ptr1 (Pseudomonas tomato race 1) locus in Solanum lycopersicoides confers resistance to strains of Pseudomonas syringae pv. tomato expressing AvrRpt2 and Ralstonia pseudosolanacearum expressing RipBN. Here we describe the identification and phylogenetic analysis of the Ptr1 gene. A single recombinant among 585 F2 plants segregating for the Ptr1 locus was discovered that narrowed the Ptr1 candidates to eight nucleotide-binding leucine-rich repeat protein (NLR)-encoding genes. From analysis of the gene models in the S. lycopersicoides genome sequence and RNA-Seq data, two of the eight genes emerged as the strongest candidates for Ptr1. One of these two candidates was found to encode Ptr1 based on its ability to mediate recognition of AvrRpt2 and RipBN when it was transiently expressed with these effectors in leaves of Nicotiana glutinosa. The ortholog of Ptr1 in tomato and in Solanum pennellii is a pseudogene. However, a functional Ptr1 ortholog exists in N. benthamiana and potato and both mediate recognition of AvrRpt2 and RipBN. In apple and Arabidopsis, recognition of AvrRpt2 is mediated by the Mr5 and RPS2 proteins, respectively. Phylogenetic analysis places Ptr1 in a distinct clade compared to Mr5 and RPS2 and it therefore appears to have arisen by convergent evolution for recognition of AvrRpt2.

Source connections

Published article ↗

Explore related subjects

plant biology Preprint

Keep this discovery

Explore connections, maps & timelines

BibTeX RIS

Mazo-Molina, D. C., Mainiero, S., Haefner, B. J., Bednarek, R., Zhang, J., Feder, A., Shi, K., Strickler, S., Martin, G. B.. 2020-03-06. Ptr1 evolved convergently with RPS2 and Mr5 to mediate recognition of AvrRpt2 in diverse solanaceous species. https://doi.org/10.1101/2020.03.05.979484

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Combined heat and drought stress alters chromatin accessibility and primes potato abscisic acid biosynthesis

Due to climate change, abiotic stresses get increasingly more frequent, in a combined and recurrent manner in the same growing season. Chromatin accessibility enables efficient responses to combined stress and priming for reoccurring stresses. To study the regulatory basis of priming, we profiled chromatin accessibility and gene expression in leaves of two genetically distinct potato cultivars after prolonged heat, drought, waterlogging, and combined heat and drought. We show that most accessibility changes are stress-specific, however, drought stress elicits a distinct transcriptional response as compared to combined heat and drought stress, with strong chaperone induction and dampened abscisic acid signalling, despite water deficit. A second cycle of combined stress reveals transcriptional memory of abscisic acid biosynthesis gene StNCED3 and its transcriptional activator StWRKY33b, providing a new mechanistic insight of abiotic stress memory in a staple crop important for global food security.

plant biology↗

bioRxiv2026

High-throughput microarray analysis provides new insight into optimising Rubisco yield from diverse plants

Interest in plant-based proteins is increasing due to environmental, ethical, and health considerations. Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), the most abundant protein on Earth, is present in all green leafy biomass and possesses excellent nutritional and functional properties. Despite its potential, Rubisco remains underutilised because extraction methods are often costly, inefficient, and influenced by species-specific differences. Moreover, the impact on Rubisco yield of cell wall-protein interactions remains poorly understood. We applied Microarray Polymer Profiling (MAPP), a high-throughput platform for simultaneous polysaccharide and protein mapping, to characterise diverse leafy biomass sources. This approach revealed interspecies variation and glycan-protein interactions that influence protein extractability and these insights inform biomass selection and optimisation of extraction protocols to improve Rubisco yield. MAPP was also used to evaluate the effects of carbohydrate-active enzymes on Rubisco recovery through targeted cell wall modification.

plant biology↗

bioRxiv2026

Leaf ionomic stability shapes drought adaptation in pearl millet

Pearl millet is a staple cereal of semi-arid West Africa, where early-season water deficit constrains vegetative establishment and yield. While the genetic architecture of the pearl millet foliar ionome has been characterised under well-watered conditions, how this ionome reorganises under drought, and whether this reorganisation has a distinct genetic basis, remains unknown. We profiled the drought-response of 17 foliar elements in 175 diverse pearl millet inbred lines over two seasons in Senegal. The foliar concentration of two co-regulated groups of elements changed reproducibly under early water stress across both years. Leaf ion stability, rather than plasticity, was associated with the maintenance of flowering time and plant biomass, suggesting that drought adaptation in pearl millet relies more on ionomic stability than on adaptive shifts in elemental composition. Among the 17 elements, only potassium showed a significant genotype-by-treatment interaction suggesting that genetic variation contributes to differences in potassium response to drought. Genome-wide association mapping on potassium plasticity in response to drought identified a locus, designated qKP-6, that limits potassium depletion under stress without penalising constitutive potassium levels. This locus represents a candidate region for the genetic control of potassium plasticity under drought. This work provides new insights into the genetic control of mineral nutrition under water deficit in pearl millet, and highlights leaf potassium concentration as a genetically controlled component of drought-responsive ionomic variation with potential implications for drought tolerance.

plant biology↗