The Cabbage Experiment
Growth of R. capsulatus under different salt conditions. Absorbance (600 nm) measured for control and varying concentrations of NaCl and sea salt
Growth of cabbages at control, 1% w/v NaCl, and 1% w/v sea salt. The length of the stem, roots, and five seeds were measured, and average values were recorded. The blue bar represents the control group, the orange bar represents the 1 % NaCl group, and the green bar represents 1% sea salt group.
Cabbage growth when treated with R. capsulatus, 1 % NaCl, and 1 % sea salt separately, via spraying method. The changes in the growth over 3, 6, and 10 days were observed.
Stem (left) and root (right) growth of cabbages when treated with R. capsulatus, 1 % NaCl, and 1 % sea salt separately via spraying method. The changes in the growth over 3, 6, and 10 days were observed.
Total growth of cabbages with varying amounts of R. capsulatus, 0 μL, 10 μL, 20 μL, and 30 μL combined with no salt, NaCl, and sea salt. The length of stem, roots, and total stem and roots of five seeds were measured, and average values were recorded. The blue bar represents the R0 group, the orange bar represents the R10 group, the grey bar represents the R20 group, and the yellow bar represents the R30 group.
Absorbance of chlorophyll in leaves of cabbages treated with varying amounts of R. capsulatus, 0 μL, 10 μL, 20 μL, and 30 μL, each represented by blue, orange, grey, and yellow bars, combined with no salt, 1 % w/v NaCl, and 1 % w/v sea salt. The control group indicates no salt. The absorbance of the leaves collected from the five cabbage plants at each concentration was measured at 663 nm and 645 nm, each representing chlorophyll a and b, respectively. The absorbance value was then divided into the number of cabbage seeds from which the leaves were collected.
Impact of IAA production by R. capsulatus on salt stress-related gene expression, each row representing BrZHD10 and Bactin, with each expression labeled below.
Absorbance of chlorophyll in leaves of cabbages treated with 1 % w/v NaCl and 1% w/v sea salt. The absorbance of the leaves collected from the five cabbage plants at each concentration was measured at 663 nm and 645 nm, each representing chlorophyll a and b, respectively. The absorbance value was then divided into the number of cabbage seeds from which the leaves were collected. The blue bar represents absorbance at 663 nm, while the orange bar represents 645 nm.
Growth of cabbages with R. capsulatus. The control group indicates no R. capsulatus. The number in front of X indicates the dilution ratio. The length of the stem, roots, and the total stem and roots of the five seeds were measured, and the average values were taken.
Stem growth of cabbages with varying amounts of R. capsulatus, 0 μL, 10 μL, 20 μL, and 30 μL combined with no salt, NaCl, and sea salt. The length of stem, roots, and total stem and roots of five5 seeds were measured, and average values were recorded. The blue bar represents the R0 group, the orange bar represents the R10 group, the grey bar represents the R20 group, and the yellow bar represents the R30 group.
Root growth of cabbages with varying amounts of R. capsulatus, 0 μL, 10 μL, 20 μL, and 30 μL combined with no salt, NaCl, and sea salt. The length of stem, roots, and total stem and roots of five seeds were measured, and average values were recorded. The blue bar represents the R0 group, the orange bar represents the R10 group, the grey bar represents the R20 group, and the yellow bar represents the R30 group.
Impact of IAA production by R. capsulatus on salt stress-related gene expression, shown through relative intensity (%) of each gene expression.
Data Analysis
Conclusion
Our research highlights the remarkable potential of Rhodobacter capsulatus in promoting cabbage growth under saline conditions, making it a valuable solution for addressing soil salinization. By producing indole-3-acetic acid (IAA), the bacterium helps plants withstand the stress caused by high salt levels, improving their overall growth, including stem length, root length, and biomass. Additionally, R. capsulatus demonstrates antifungal properties, providing a dual benefit by potentially replacing chemical fungicides. This aligns with the growing need for eco-friendly solutions in agriculture, making it a sustainable alternative for regions facing soil salinization challenges.