Curá José Alfredo, Franz Diego Reinaldo, Filosofía Julián Ezequiel, Balestrasse Karina Beatríz, Burgueño Lautaro Exequiel
Facultad de Agronomía, Cátedra de Bioquímica, Universidad de Buenos Aires, Avenida San Martín 4453, Ciudad Autónoma de Buenos Aires C1417DSE, Argentina.
Microorganisms. 2017 Jul 26;5(3):41. doi: 10.3390/microorganisms5030041.
Stress drought is an important abiotic factor that leads to immense losses in crop yields around the world. Strategies are urgently needed to help plants adapt to drought in order to mitigate crop losses. Here we investigated the bioprotective effects of inoculating corn grown under drought conditions with two types of plant growth-promoting rhizobacteria (PGPR), , strain SP-7, and , strain Z-152. Plants inoculated with the bacteria were grown in a greenhouse with perlite as a substrate. Two hydric conditions were tested: normal well-watered conditions and drought conditions. Compared to control non-inoculated plants, those that were inoculated with PGPR bacteria showed a higher tolerance to the negative effects of water stress in drought conditions, with higher biomass production; higher carbon, nitrogen, and chlorophyll levels; and lower levels of abscisic acid and ethylene, which are plant hormones that affect the stress response. The oxidative stress levels of these plants were similar to those of non-inoculated plants grown in well-watered conditions, showing fewer injuries to the cell membrane. We also noted higher relative water content in the vegetal tissue and better osmoregulation in drought conditions in inoculated plants, as reflected by significantly lower proline content. Finally, we observed lower gene expression of in the inoculated plants; notably, is involved in the biosynthesis of abscisic acid. Taken together, these results demonstrate that these bacteria could be used to help plants cope with the negative effects of drought stress conditions.
干旱胁迫是导致全球农作物产量大幅损失的重要非生物因素。迫切需要采取策略来帮助植物适应干旱，以减轻作物损失。在此，我们研究了用两种促植物生长根际细菌（PGPR），即SP-7菌株和Z-152菌株，对接种在干旱条件下生长的玉米的生物保护作用。接种了这些细菌的植物在以珍珠岩为基质的温室中生长。测试了两种水分条件：正常充分浇水条件和干旱条件。与未接种的对照植物相比，接种了PGPR细菌的植物在干旱条件下对水分胁迫的负面影响表现出更高的耐受性，具有更高的生物量产量、更高的碳、氮和叶绿素水平，以及更低水平的脱落酸和乙烯，这两种植物激素会影响胁迫反应。这些植物的氧化应激水平与在充分浇水条件下生长的未接种植物相似，对细胞膜的损伤较少。我们还注意到接种植物在干旱条件下植物组织中的相对含水量更高，渗透调节更好，这表现为脯氨酸含量显著降低。最后，我们观察到接种植物中参与脱落酸生物合成的基因表达较低。综上所述，这些结果表明这些细菌可用于帮助植物应对干旱胁迫条件的负面影响。
