TY - JOUR
T1 - Endophytic Bacteria Colonizing the Petiole of the Desert Plant Zygophyllum dumosum Boiss
T2 - Possible Role in Mitigating Stress
AU - Srinivasan, Jansirani
AU - Khadka, Janardan
AU - Novoplansky, Nurit
AU - Gillor, Osnat
AU - Grafi, Gideon
N1 - Funding Information:
Funding: This research was funded by the the Sol Leshin Program for BGU-UCLA Academic Cooperation and partially supported by the Interdisciplinary Master Scholarship from Ben Gurion University of the Negev.
Publisher Copyright:
© 2022 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2022/2/1
Y1 - 2022/2/1
N2 - Zygophyllum dumosum is a dominant shrub in the Negev Desert whose survival is accom-plished by multiple mechanisms including abscission of leaflets to reduce whole plant transpiration while leaving the fleshy, wax-covered petioles alive but dormant during the dry season. Petioles that can survive for two full growing seasons maintain cell component integrity and resume metabolic activity at the beginning of the winter. This remarkable survival prompted us to investigate endo-phytic bacteria colonizing the internal tissues of the petiole and assess their role in stress tolerance. Twenty-one distinct endophytes were isolated by culturing from surface-sterile petioles and identified by sequencing of the 16S rDNA. Sequence alignments and the phylogenetic tree clustered the isolated endophytes into two phyla, Firmicutes and Actinobacteria. Most isolated endophytes displayed a relatively slow growth on nutrient agar, which was accelerated by adding petiole extracts. Metabolic analysis of selected endophytes showed several common metabolites whose level is affected by petiole extract in a species-dependent manner including phosphoric acid, pyroglutamic acid, and glutamic acid. Other metabolites appear to be endophyte-specific metabolites, such as proline and trehalose, which were implicated in stress tolerance. These results demonstrate the existence of multiple endophytic bacteria colonizing Z. dumosum petioles with the potential role in maintaining cell integrity and functionality via synthesis of multiple beneficial metabolites that mitigate stress and contribute to stress tolerance.
AB - Zygophyllum dumosum is a dominant shrub in the Negev Desert whose survival is accom-plished by multiple mechanisms including abscission of leaflets to reduce whole plant transpiration while leaving the fleshy, wax-covered petioles alive but dormant during the dry season. Petioles that can survive for two full growing seasons maintain cell component integrity and resume metabolic activity at the beginning of the winter. This remarkable survival prompted us to investigate endo-phytic bacteria colonizing the internal tissues of the petiole and assess their role in stress tolerance. Twenty-one distinct endophytes were isolated by culturing from surface-sterile petioles and identified by sequencing of the 16S rDNA. Sequence alignments and the phylogenetic tree clustered the isolated endophytes into two phyla, Firmicutes and Actinobacteria. Most isolated endophytes displayed a relatively slow growth on nutrient agar, which was accelerated by adding petiole extracts. Metabolic analysis of selected endophytes showed several common metabolites whose level is affected by petiole extract in a species-dependent manner including phosphoric acid, pyroglutamic acid, and glutamic acid. Other metabolites appear to be endophyte-specific metabolites, such as proline and trehalose, which were implicated in stress tolerance. These results demonstrate the existence of multiple endophytic bacteria colonizing Z. dumosum petioles with the potential role in maintaining cell integrity and functionality via synthesis of multiple beneficial metabolites that mitigate stress and contribute to stress tolerance.
KW - 16S rRNA genes
KW - Actinobacteria
KW - Desert plants
KW - Endophyte metabolites
KW - Firmicutes
KW - Phyllosphere endophytic bacteria
KW - Stress-related metabolites
KW - Zygophyllum dumosum
UR - http://www.scopus.com/inward/record.url?scp=85124319552&partnerID=8YFLogxK
U2 - 10.3390/plants11040484
DO - 10.3390/plants11040484
M3 - Article
C2 - 35214818
AN - SCOPUS:85124319552
SN - 2223-7747
VL - 11
JO - Plants
JF - Plants
IS - 4
M1 - 484
ER -