Zboralski Antoine, Saadia Hara, Novinscak Amy, Filion Martin
Saint-Jean-sur-Richelieu Research and Development Centre, Agriculture and Agri-Food Canada, 430 Gouin Boulevard, Saint-Jean-sur-Richelieu, QC J3B 3E6, Canada.
Department of Biology, Université de Moncton, 18 avenue Antonine-Maillet, Moncton, NB E1A 3E9, Canada.
Microorganisms. 2022 Mar 19;10(3):660. doi: 10.3390/microorganisms10030660.
Rhizosphere colonization by phytobeneficial Pseudomonas spp. is pivotal in triggering their positive effects on plant health. Many Pseudomonas spp. Determinants, involved in rhizosphere colonization, have already been deciphered. However, few studies have explored the role played by specific plant genes in rhizosphere colonization by these bacteria. Using isogenic Arabidopsis thaliana mutants, we studied the effect of 20 distinct plant genes on rhizosphere colonization by two phenazine-producing P. chlororaphis strains of biocontrol interest, differing in their colonization abilities: DTR133, a strong rhizosphere colonizer and ToZa7, which displays lower rhizocompetence. The investigated plant mutations were related to root exudation, immunity, and root system architecture. Mutations in smb and shv3, both involved in root architecture, were shown to positively affect rhizosphere colonization by ToZa7, but not DTR133. While these strains were not promoting plant growth in wild-type plants, increased plant biomass was measured in inoculated plants lacking fez, wrky70, cbp60g, pft1 and rlp30, genes mostly involved in plant immunity. These results point to an interplay between plant genotype, plant growth and rhizosphere colonization by phytobeneficial Pseudomonas spp. Some of the studied genes could become targets for plant breeding programs to improve plant-beneficial Pseudomonas rhizocompetence and biocontrol efficiency in the field.
植物有益假单胞菌属在根际的定殖对于触发其对植物健康的积极影响至关重要。许多参与根际定殖的假单胞菌属决定因素已被破译。然而，很少有研究探讨特定植物基因在这些细菌根际定殖中所起的作用。我们使用同基因的拟南芥突变体，研究了20个不同的植物基因对两种具有生物防治意义的产吩嗪类绿针假单胞菌菌株根际定殖的影响，这两种菌株在定殖能力上有所不同：DTR133是一种强大的根际定殖者，而ToZa7的根际竞争力较低。所研究的植物突变与根系分泌物、免疫和根系结构有关。参与根系结构的smb和shv3突变被证明对ToZa7的根际定殖有积极影响，但对DTR133没有影响。虽然这些菌株在野生型植物中不促进植物生长，但在缺乏fez、wrky70、cbp60g、pft1和rlp30基因（这些基因大多参与植物免疫）的接种植物中测量到了植物生物量的增加。这些结果表明植物基因型、植物生长和植物有益假单胞菌属在根际的定殖之间存在相互作用。一些所研究的基因可能成为植物育种计划的目标，以提高植物有益假单胞菌在田间的根际竞争力和生物防治效率。
