AUTHOR=Hou Yaling , Zeng Wenzhi , Ao Chang , Luo Ying , Wang Zhao , Hou Menglu , Huang Jiesheng 

TITLE=Bacillus atrophaeus WZYH01 and Planococcus soli WZYH02 Improve Salt Tolerance of Maize (Zea mays L.) in Saline Soil

JOURNAL=Frontiers in Plant Science

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2022.891372

DOI=10.3389/fpls.2022.891372

ISSN=1664-462X

ABSTRACT=<p>With the increasing shortage of land resources and people’s attention to the ecological environment, the application of microbial fertilizer with natural soil microorganisms as the main component has attracted increasing attention in saline agriculture. In this study, two salt-tolerant strains, YL07 (<italic>Bacillus atrophaeus</italic>) and YL10 (<italic>Planococcus soli</italic>), were isolated from maize (<italic>Zea mays</italic> L.) rhizosphere soil with a saturated conductivity (EC<sub>e</sub>) of 6.13 dS/m and pH of 8.32 (Xinjiang, China). The effects of <italic>B. atrophaeus</italic> WZYH01 (YL07) and <italic>Planococcus soli</italic> WZYH02 (YL10) on the growth and development of maize (<italic>Zea mays</italic> L.) under salt stress (EC<sub>e</sub> = 5.9 dS/m) were further studied. The results showed that compared with uninoculation, inoculation with <italic>B. atrophaeus</italic> WZYH01 and <italic>Planococcus soli</italic> WZYH02 significantly improved maize growth performance, biomass yield, and antioxidant levels under salt stress, and the effect of <italic>Planococcus soli</italic> WZYH02 was more prominent than the effect of <italic>B. atrophaeus</italic> WZYH01. Moreover, inoculation with <italic>B. atrophaeus</italic> WZYH01 and <italic>Planococcus soli</italic> WZYH02 protected maize from salt stress by regulating plant hormone [IAA and abscisic acid (ABA)] levels and increasing nutrient acquisition. In addition, the tested strains were most efficient for maize growth and health, increasing the content of K<sup>+</sup> accompanied by an effective decrease in Na<sup>+</sup> in maize tissues. The transcription levels of salt tolerance genes (<italic>ZMNHX1</italic>, <italic>ZMNHX2</italic>, <italic>ZMHKT</italic>, <italic>ZMWRKY58</italic>, and <italic>ZMDREB2A</italic>) in inoculated maize were also dramatically higher than the transcription levels of the specified salt tolerance genes in uninoculated maize. In conclusion, <italic>B. atrophaeus</italic> WZYH01 and <italic>Planococcus soli</italic> WZYH02 can alleviate the harmful effects of salt stress on crop growth, thereby promoting sustainable agricultural development.</p>