# High genetic abundance of Rpi-blb2/Mi-1.2/Cami gene family in Solanaceae

## TL;DR

This study explores a plant resistance gene family in Solanaceae plants, revealing high genetic diversity and copy number variation across species.

## Contribution

The paper identifies a unique resistance gene family with high genetic abundance and divergence across Solanaceae species.

## Key findings

- The Rpi-blb2/Mi-1.2/Cami gene family shows large copy number variation and high divergence within and between species.
- Frequent frameshift mutations and gene conversion events were observed in the LRR regions of this gene family.
- The genetic diversity suggests that multi-resistance is a common trait in this resistance gene family.

## Abstract

Three NBS-LRR genes, Rpi-blb2, Mi-1.2, and Cami, constitute a very special plant resistance gene family. These genes confer resistance against 4 distantly related pathogen species in 3 different Solanaceae hosts. To characterize this noted resistance, we conducted a series of studies on this gene family.

First, homologs of this gene family were identified in the pepper, tomato and potato genomes. This revealed a large variation in copy number within this gene family among species and a great divergence was found both between and within species. To gain more information pertaining to gene resistance within this family, 121 LRR regions were cloned in 16 different wild/cultivated potato accessions. Again, frequent copy number variations and a high level of divergence between homolog were observed common among accessions. The divergence within species was so high that it reaches the level of divergence between species. Also, frequent frameshift mutations and abundant gene conversion events were identified in these LRR regions.

Our findings suggest that this family harbors an unusually high level of genetic abundance, making it of particular interest. Together with other reported examples, our study also provides evidence that multi-resistance is a common trait in R gene families like this.

The online version of this article (doi:10.1186/s12862-015-0493-z) contains supplementary material, which is available to authorized users.