Ayelet Caspi-Fluger
Einat Zchori-Fein
Plants are infected by many pathogens, among them bacteria. Some pathogenic bacteria enter the plant through a wound or natural opening; others colonize the salivary glands of an insect vector and are injected into the plant tissue when the insect feeds. Insects of the order Hemiptera are common vectors of plant bacterial diseases and also host symbiotic bacteria, which may be mutualists, commensals, or pathogens. While working on several hemipteran-symbiont systems, we consistently found high similarities between bacterial genes associated with hemipterans and bacterial genes associated with plants, some of the latter referred to as plant pathogens. Therefore, we assume that some bacteria may be shared by hemipterans and plants, first evolving as a symbiont of one and later, via feeding, becoming adapted to the other. Here we present five examples of hemipteran symbionts that are highly similar in their 16S rRNA gene sequence to plant pathogens and focus on two specific examples. We discuss the possibility of hemipteran symbionts' evolution into plant pathogens and vice versa, as well as the importance of possible changes in these bacteria's lifestyles to herbivores and humans.
Ayelet Caspi-Fluger
Einat Zchori-Fein
Plants are infected by many pathogens, among them bacteria. Some pathogenic bacteria enter the plant through a wound or natural opening; others colonize the salivary glands of an insect vector and are injected into the plant tissue when the insect feeds. Insects of the order Hemiptera are common vectors of plant bacterial diseases and also host symbiotic bacteria, which may be mutualists, commensals, or pathogens. While working on several hemipteran-symbiont systems, we consistently found high similarities between bacterial genes associated with hemipterans and bacterial genes associated with plants, some of the latter referred to as plant pathogens. Therefore, we assume that some bacteria may be shared by hemipterans and plants, first evolving as a symbiont of one and later, via feeding, becoming adapted to the other. Here we present five examples of hemipteran symbionts that are highly similar in their 16S rRNA gene sequence to plant pathogens and focus on two specific examples. We discuss the possibility of hemipteran symbionts' evolution into plant pathogens and vice versa, as well as the importance of possible changes in these bacteria's lifestyles to herbivores and humans.