Abstract
The ability of cycads to grow in harsh environments is thought to be associated with endophytic bacteria in their roots. This study aimed to characterize endophytic bacteria from Cycas rumphii and Dioon spinulosum as stress-tolerant plant growth-promoting bacteria (PGPB). Fine roots of C. rumphii and D. spinulosum were isolated using serial dilution plating and characterized through colony morphological observation, hypersensitivity, antagonistic activity, PGP activity, and abiotic stress tolerance assays. Fourteen isolates were obtained (eight from C. rumphii and six from D. spinulosum), with higher abundance and diversity in D. spinulosum (2.51 × 10¹⁰ CFU/g; H′ = 2.016) than C. rumphii (4.64 × 10⁹ CFU/g; H′ = 1.752). All isolates were non-pathogenic; 92% fixed nitrogen, 92% solubilized phosphate, and one (DS1A) produced IAA (0.200 ppm). Four isolates showed antagonism against Xanthomonas campestris (0.40–0.67 cm inhibition) and tolerance to drought, salinity (5–10%), and moderate heat, with growth at pH 5–6. Molecular identification by 16S rRNA sequencing revealed that CR1A, CR1B, and DS1B belong to Stenotrophomonas maltophilia, whereas DS1A belongs to Bacillus sp. These findings highlight cycads as a source of endophytic PGPB candidates for supporting plant health, particularly when grown in the environmental stress condition areas.
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Claims 12
Claim · model-written summary
Endophyte abundance and diversity were higher in Dioon spinulosum than in Cycas rumphii.
- Taxon
- D. spinulosum
Dioon spinulosume0 - Outcome
- abundance and diversitye0
- Direction
- highere0
- Value
- 2.51 × 10¹⁰ CFU/ge0
- Comparator
- C. rumphiie0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“with higher abundance and diversity in D. spinulosum (2.51 × 10¹⁰ CFU/g; H′ = 2.016) than C. rumphii”
Claim · model-written summary
All endophytic isolates from both cycad species were non-pathogenic.
- Taxon
- Cycas rumphii and Dioon spinulosum
Cycas rumphiiDioon spinulosumt0 - Outcome
- non-pathogenice1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Endophytic Bacteria Originating from Cycas rumphii and Dioon spinulosum”
e1“All isolates were non-pathogenic”
Claim · model-written summary
Of the isolates, 92% fixed nitrogen.
- Taxon
- Cycas rumphii and Dioon spinulosumCycas rumphiiDioon spinulosumt0
- Outcome
- fixed nitrogene1
- Value
- 92%e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Endophytic Bacteria Originating from Cycas rumphii and Dioon spinulosum”
e1“92% fixed nitrogen”
Claim · model-written summary
Of the isolates, 92% solubilized phosphate.
- Taxon
- Cycas rumphii and Dioon spinulosumCycas rumphiiDioon spinulosumt0
- Outcome
- solubilized phosphatee1
- Value
- 92%e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Endophytic Bacteria Originating from Cycas rumphii and Dioon spinulosum”
e1“92% solubilized phosphate”
Claim · model-written summary
Isolate DS1A produced IAA at 0.200 ppm.
- Taxon
- Cycas rumphii and Dioon spinulosumCycas rumphiiDioon spinulosumt0
- Material
- DS1Ae1
- Outcome
- produced IAAe1
- Value
- 0.200 ppme1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Endophytic Bacteria Originating from Cycas rumphii and Dioon spinulosum”
e1“one (DS1A) produced IAA (0.200 ppm)”
Claim · model-written summary
Four isolates antagonised Xanthomonas campestris with inhibition zones of 0.40–0.67 cm.
- Taxon
- Cycas rumphii and Dioon spinulosumCycas rumphiiDioon spinulosumt0
- Interactor
- Xanthomonas campestris
_(25868012152).jpg?width=60)
Xanthomonas campestrise1pathogen - Second interactor
- isolatese1biocontrol_agent
- Outcome
- antagonisme1
- Value
- 0.40–0.67 cme1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
_(25868012152).jpg?width=500)
Verbatim
t0“Endophytic Bacteria Originating from Cycas rumphii and Dioon spinulosum”
e1“Four isolates showed antagonism against Xanthomonas campestris (0.40–0.67 cm inhibition)”
Claim · model-written summary
Four isolates tolerated salinity of 5–10%.
- Taxon
- Cycas rumphii and Dioon spinulosumCycas rumphiiDioon spinulosumt0
- Treatment
- salinitye1
- Outcome
- tolerancee1
- Value
- 5–10%e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Endophytic Bacteria Originating from Cycas rumphii and Dioon spinulosum”
e1“tolerance to drought, salinity (5–10%), and moderate heat”
Claim · model-written summary
Four isolates tolerated drought.
- Taxon
- Cycas rumphii and Dioon spinulosumCycas rumphiiDioon spinulosumt0
- Treatment
- droughte1
- Outcome
- tolerancee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Endophytic Bacteria Originating from Cycas rumphii and Dioon spinulosum”
e1“tolerance to drought, salinity (5–10%), and moderate heat”
Claim · model-written summary
Four isolates tolerated moderate heat.
- Taxon
- Cycas rumphii and Dioon spinulosumCycas rumphiiDioon spinulosumt0
- Treatment
- moderate heate1
- Outcome
- tolerancee1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Endophytic Bacteria Originating from Cycas rumphii and Dioon spinulosum”
e1“tolerance to drought, salinity (5–10%), and moderate heat”
Claim · model-written summary
Four isolates grew at pH 5–6.
- Taxon
- Cycas rumphii and Dioon spinulosumCycas rumphiiDioon spinulosumt0
- Outcome
- growthe1
- Value
- pH 5–6e1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Endophytic Bacteria Originating from Cycas rumphii and Dioon spinulosum”
e1“with growth at pH 5–6”
Claim · model-written summary
Isolates CR1A, CR1B and DS1B were identified as Stenotrophomonas maltophilia by 16S rRNA sequencing.
- Taxon
- Cycas rumphii and Dioon spinulosumCycas rumphiiDioon spinulosumt0
- Material
- CR1A, CR1B, and DS1Be0
- Interactor
- Stenotrophomonas maltophilia
Stenotrophomonas maltophiliae0symbiont - Outcome
- Molecular identification by 16S rRNA sequencinge1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Endophytic Bacteria Originating from Cycas rumphii and Dioon spinulosum”
e0“CR1A, CR1B, and DS1B belong to Stenotrophomonas maltophilia”
e1“Molecular identification by 16S rRNA sequencing revealed”
Claim · model-written summary
Isolate DS1A was identified as Bacillus sp. by 16S rRNA sequencing.
- Taxon
- Cycas rumphii and Dioon spinulosumCycas rumphiiDioon spinulosumt0
- Material
- DS1Ae0
- Interactor
- Bacillus sp.e0symbiont
- Outcome
- Molecular identification by 16S rRNA sequencinge1
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
t0“Endophytic Bacteria Originating from Cycas rumphii and Dioon spinulosum”
e0“whereas DS1A belongs to Bacillus sp.”
e1“Molecular identification by 16S rRNA sequencing revealed”