Endophytic <i>Pseudomonas</i> sp. from <i>Agave palmeri</i> Participate in the Rhizophagy Cycle and Act as Biostimulants in Crop Plants

Plant growth-promoting bacteria are generating increasing interest in the agricultural industry as a promising alternative to traditional chemical fertilizers; however, much of the focus has been on rhizosphere bacteria. Bacterial endophytes are another promising source of plant growth-promoting bac...

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Main Authors: Qiuwei Zhang, Kathryn L. Kingsley, James F. White
Format: Article
Language:English
Published: MDPI AG 2022-12-01
Series:Biology
Subjects:
Online Access:https://www.mdpi.com/2079-7737/11/12/1790
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author Qiuwei Zhang
Kathryn L. Kingsley
James F. White
author_facet Qiuwei Zhang
Kathryn L. Kingsley
James F. White
author_sort Qiuwei Zhang
collection DOAJ
description Plant growth-promoting bacteria are generating increasing interest in the agricultural industry as a promising alternative to traditional chemical fertilizers; however, much of the focus has been on rhizosphere bacteria. Bacterial endophytes are another promising source of plant growth-promoting bacteria, and though many plants have already been prospected for beneficial microbes, desert plants have been underrepresented in such studies. In this study, we show the growth-promoting potential of five strains of endophytic <i>Pseudomonas</i> sp. isolated from <i>Agave palmeri</i>, an agave from the Sonoran Desert. When inoculated onto Kentucky bluegrass, clover, carrot, coriander, and wheat, endophytic <i>Pseudomonas</i> sp. increased seedling root lengths in all hosts and seedling shoot lengths in Kentucky bluegrass, carrot, and wheat. Transformation of the <i>Pseudomonas</i> sp. strain P3AW to express the fluorescent protein mCherry revealed that <i>Pseudomonas</i> sp. becomes endophytic in non-native hosts and participates in parts of the rhizophagy cycle, a process by which endophytic bacteria cycle between the soil and roots, bringing in nutrients from the soil which are then extracted through reactive oxygen-mediated bacterial degradation in the roots. Tracking of the <i>Pseudomonas</i> sp. strain P3AW also provided evidence for a system of endophyte, or endophyte cell content, transport via the vascular bundle. These results provide further evidence of the rhizophagy cycle in plants and how it relates to growth promotion in plants by biostimulant bacteria.
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spelling doaj.art-baa400601e7d4fe090ed3c444128ae322023-11-24T13:23:32ZengMDPI AGBiology2079-77372022-12-011112179010.3390/biology11121790Endophytic <i>Pseudomonas</i> sp. from <i>Agave palmeri</i> Participate in the Rhizophagy Cycle and Act as Biostimulants in Crop PlantsQiuwei Zhang0Kathryn L. Kingsley1James F. White2Department of Plant Biology, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, NJ 08901, USADepartment of Plant Biology, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, NJ 08901, USADepartment of Plant Biology, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, NJ 08901, USAPlant growth-promoting bacteria are generating increasing interest in the agricultural industry as a promising alternative to traditional chemical fertilizers; however, much of the focus has been on rhizosphere bacteria. Bacterial endophytes are another promising source of plant growth-promoting bacteria, and though many plants have already been prospected for beneficial microbes, desert plants have been underrepresented in such studies. In this study, we show the growth-promoting potential of five strains of endophytic <i>Pseudomonas</i> sp. isolated from <i>Agave palmeri</i>, an agave from the Sonoran Desert. When inoculated onto Kentucky bluegrass, clover, carrot, coriander, and wheat, endophytic <i>Pseudomonas</i> sp. increased seedling root lengths in all hosts and seedling shoot lengths in Kentucky bluegrass, carrot, and wheat. Transformation of the <i>Pseudomonas</i> sp. strain P3AW to express the fluorescent protein mCherry revealed that <i>Pseudomonas</i> sp. becomes endophytic in non-native hosts and participates in parts of the rhizophagy cycle, a process by which endophytic bacteria cycle between the soil and roots, bringing in nutrients from the soil which are then extracted through reactive oxygen-mediated bacterial degradation in the roots. Tracking of the <i>Pseudomonas</i> sp. strain P3AW also provided evidence for a system of endophyte, or endophyte cell content, transport via the vascular bundle. These results provide further evidence of the rhizophagy cycle in plants and how it relates to growth promotion in plants by biostimulant bacteria.https://www.mdpi.com/2079-7737/11/12/1790plant growth-promoting bacteriaplant–microbe interactionsendophytesbiostimulantsrhizophagy cycleconfocal microscopy
spellingShingle Qiuwei Zhang
Kathryn L. Kingsley
James F. White
Endophytic <i>Pseudomonas</i> sp. from <i>Agave palmeri</i> Participate in the Rhizophagy Cycle and Act as Biostimulants in Crop Plants
Biology
plant growth-promoting bacteria
plant–microbe interactions
endophytes
biostimulants
rhizophagy cycle
confocal microscopy
title Endophytic <i>Pseudomonas</i> sp. from <i>Agave palmeri</i> Participate in the Rhizophagy Cycle and Act as Biostimulants in Crop Plants
title_full Endophytic <i>Pseudomonas</i> sp. from <i>Agave palmeri</i> Participate in the Rhizophagy Cycle and Act as Biostimulants in Crop Plants
title_fullStr Endophytic <i>Pseudomonas</i> sp. from <i>Agave palmeri</i> Participate in the Rhizophagy Cycle and Act as Biostimulants in Crop Plants
title_full_unstemmed Endophytic <i>Pseudomonas</i> sp. from <i>Agave palmeri</i> Participate in the Rhizophagy Cycle and Act as Biostimulants in Crop Plants
title_short Endophytic <i>Pseudomonas</i> sp. from <i>Agave palmeri</i> Participate in the Rhizophagy Cycle and Act as Biostimulants in Crop Plants
title_sort endophytic i pseudomonas i sp from i agave palmeri i participate in the rhizophagy cycle and act as biostimulants in crop plants
topic plant growth-promoting bacteria
plant–microbe interactions
endophytes
biostimulants
rhizophagy cycle
confocal microscopy
url https://www.mdpi.com/2079-7737/11/12/1790
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AT kathrynlkingsley endophyticipseudomonasispfromiagavepalmeriiparticipateintherhizophagycycleandactasbiostimulantsincropplants
AT jamesfwhite endophyticipseudomonasispfromiagavepalmeriiparticipateintherhizophagycycleandactasbiostimulantsincropplants