AUTHOR=Tasnim Anika , Jahan Israt , Azim Tomalika , Karmoker Dola , Seraj Zeba I. 

TITLE=Paired growth of cultivated and halophytic wild rice under salt stress induces bacterial endophytes and gene expression responses

JOURNAL=Frontiers in Plant Science

VOLUME=14

YEAR=2023

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2023.1244743

DOI=10.3389/fpls.2023.1244743

ISSN=1664-462X

ABSTRACT=<sec><title>Introduction</title><p>Utilizing salt-affected marginal lands in coastal regions can help meet the growing demand for rice. We explored a nature-based solution involving wild halophytic rice (<italic>O. coarctata, Oc</italic>) and commercial rice BRRI Dhan 67 (<italic>O. sativa, Os</italic>) grown in close proximity to each other under salt stress.</p></sec><sec><title>Methods</title><p>This was to investigate whether a paired planting strategy could help complement rice growth and yield under stress. We also investigated the gene expression and endophytic bacterial profiles of both <italic>Os and Oc</italic> in unpaired and paired conditions without and with salt.</p></sec><sec><title>Results</title><p>Paired plants exhibited lower salt damage indicators such as smaller reduction in plant height, electrolyte leakage and chlorophyll loss, as well as higher K<sup>+</sup>/Na<sup>+</sup> ratio under saline stress. Some of the 39 endophytic bacteria in the mutualism experiment were unique to <italic>Oc</italic> and transferred to <italic>Os</italic> when paired. Differentially expressed genes in leaves of paired <italic>Os</italic> versus unpaired <italic>Os</italic> were 1097 (994 up-regulated, 101 down-regulated) without salt and 893 (763 up-regulated, 130 down-regulated) under salt stress. The presence of <italic>Oc</italic> plants under salt stress influenced major biological processes in <italic>Os</italic>, including oxidative stress; chitinase activity; phenylalanine catabolic process and response to ABA. Protein binding and serine/threonine kinase activity were primarily affected in molecular function. The downregulated WRKY transcription factor 22 in paired conditions under salt stress played a role in the MAPK signaling pathway, reducing respiratory cell death. The upregulated auxin-responsive protein IAA18 gene, involved in hormone signaling and cell enlargement, was present only in paired plants.</p></sec><sec><title>Discussion</title><p>Our findings therefore, offer insights into developing more effective cultivation strategies for sustainable rice production.</p></sec>