Ogata-Gutiérrez Katty, Chumpitaz-Segovia Carolina, Lirio-Paredes Jesus, Finetti-Sialer Mariella M, Zúñiga-Dávila Doris
Laboratorio de Ecología Microbiana y Biotecnología, Departmento de Biología, Facultad de Ciencias, Universidad Nacional Agraria La Molina, Av. La Molina s/n, Lima, Peru.
Istituto di Bioscienze e Biorisorse, Consiglio Nazionale delle Ricerche, Via G. Amendola 165/A, 70126, Bari, Italy.
World J Microbiol Biotechnol. 2017 Oct 27;33(11):203. doi: 10.1007/s11274-017-2369-4.
Bacteria isolated from soil and rhizosphere samples collected in Peru from Andean crops were tested in vitro and in vivo to determine their potential as plant growth promoters and their ability to induce systemic resistance to Alternaria alternata in tomato plants. The isolates were identified by sequencing their 16S ribosomal RNA gene. Test for phosphate solubilization, and indolacetic acid were also carried out, together with in vitro antagonism assays in dual cultures towards the plant pathogens Fusarium solani, A. alternata and Curvularia lunata. The three most promising isolates (Pa15, Ps155, Ps168) belonged to the genus Pseudomonas. Further assays were carried out with tomato plants to assess their plant protection effect towards A. alternata and as growth promoters. Inoculation of tomato seeds with all isolates significantly enhanced seed germination, plantlets emergence and plant development. Bacterial inoculation also reduce damage level caused by A. alternata. The expression levels of three tomato genes involved in the jasmonate (AOS), ethylene responsive (ERF-2) and pathogenesis related (PR-P2) pathways were determined in plants challenged with A. alternata, alone or with each bacterial isolate, respectively. Results showed that at 24 h after infection, in absence of the pathogen, the expression level of the tested genes was very low. The presence of A. alternata alone and in combination with bacteria increased the transcripts of all genes. Data showed a potential of best performing isolate Ps168 to sustain tomato plants nutrition and activate defense-related genes for protection by pathogenic fungi.
从秘鲁安第斯作物采集的土壤和根际样本中分离出的细菌，在体外和体内进行了测试，以确定它们作为植物生长促进剂的潜力以及诱导番茄植株对链格孢菌产生系统抗性的能力。通过对其16S核糖体RNA基因进行测序来鉴定这些分离株。还进行了磷溶解和吲哚乙酸测试，以及在双培养物中对植物病原体茄类镰刀菌、链格孢菌和新月弯孢菌的体外拮抗试验。三个最有前景的分离株（Pa15、Ps155、Ps168）属于假单胞菌属。对番茄植株进行了进一步试验，以评估它们对链格孢菌的植物保护作用以及作为生长促进剂的作用。用所有分离株接种番茄种子显著提高了种子发芽率、幼苗出土率和植株发育。细菌接种还降低了链格孢菌造成的损害水平。分别在单独用链格孢菌或与每种细菌分离株共同处理的番茄植株中，测定了参与茉莉酸（AOS）、乙烯响应（ERF-2）和病程相关（PR-P2）途径的三个番茄基因的表达水平。结果表明，在感染后24小时，在没有病原体的情况下，测试基因的表达水平非常低。单独存在链格孢菌以及与细菌共同存在时，所有基因的转录本都增加了。数据显示，表现最佳的分离株Ps168有潜力维持番茄植株的营养，并激活与防御相关的基因以抵御致病真菌的侵害。
