Fig 1.
Phylogenetic tree showing the relationship of Serratia marcescens CDP-13 with other closely related bacterial strains and species.
The 16S rRNA gene sequence of closely related species was obtained from NCBI Genbank database. The tree was constructed using neighbor- joining method of software package Mega version 6.0, at the bootstrap value of n = 500.
Table 1.
Plant growth promoting traits of strain Serratia marcecens CDP-13.
Fig 2.
Ability of the isolate CDP-13 to produce (A) siderophore on CAS-agar plate and (B) to exhibit different types of motility using agar based method. Panel A, B, and C of Fig 2B represent swimming, swarming, and twitching motility respectively.
Table 2.
Biochemical and physiological properties of CDP-13 and its carbohydrate utilization pattern.
Fig 3.
The growth of wheat plants treated with Serratia marcesens CDP-13 and a plant pathogen (F. graminearum).
(A) The growth of bacterium and fungal treated plants on water agar medium, (B) Pot experiment showing growth of bacterium and fungus-treated plants in the soil.
Fig 4.
The growth of bacterium-inoculated plants was compared at different time intervals with their control-counterparts.
(A) plate based screening, (B) sprouted wheat seedlings 1,2 control; 3,4 CDP-13 inoculated seedlings, (C) growth after 15th days of germination; Panel 1 is uninoculated control plants, whereas panel 2 shows CDP-13 inoculated plant.
Fig 5.
Effect of inoculation with isolate CDP-13 on plant biomass and chlorophyll content under different concentrations of NaCl.
Different plant growth parameters were tested which included (A) Shoot length. (B) Root length (C) Fresh weight (D) Dry weight (E) Chlorophyll a (F) Chlorophyll b. Values are mean ± SD of triplicate sets (n = 15). Double asterisk ** represent the significant difference according to Duncan multiple range test (p = 0.05) as compared to control.
Table 3.
Physiochemical properties of soil used for pot study.
Fig 6.
Effect of inoculation with isolate CDP-13 on salinity induced oxidative damages in wheat plants with respect to generation of (A) MDA content (B) H2O2 content (C) O2-, and measurement of (D) Membrane stability index. Values are mean ± SD of triplicate sets (n = 15). Double asterisk ** represent the significant difference according to Duncan multiple range test (p = 0.05) as compared to control counterpart.
Fig 7.
Effect of inoculation with isolate CDP-13 on antioxidative enzymatic activities in bacterium treated and control plants under tested salt stress conditions.
(A) SOD activity (B) CAT activity(C) POX activity. Values are mean ± SD of triplicate sets (n = 15). Double asterisk ** represent the significant difference according to Duncan multiple range test (p = 0.05) as compared to control.
Fig 8.
Effect of bacterium inoculation on the production of various osmolytes in plants supplemented with various concentration of NaCl.
(A) Proline (B) Total soluble sugar under different concentration of NaCl (0 mM, 150 mM, 175 mM, 200 mM). Values are mean of three replicates ± SD (n = 15). Significant difference according to Duncan multiple range test (p = 0.05) compared to control has been denoted by Double asterisk **.
Fig 9.
Effect of bacterial inoculation on the production of (A) Auxin and (B) Total protein content under different NaCl concentration (0 mM, 150 mM, 175 mM, 200 mM). Values are mean of three replicates ± SD (n = 15). Significant difference according to Duncan multiple range test (p = 0.05) compared to control has been denoted by Double asterisk **.
Fig 10.
Assessment of the efficiency of colonization of isolate CDP-13 based on ERIC-PCR profile of bacterium colonized in wheat plants.
(Lane M: DNA ladder SM0311, Lane A: control DNA, Lane B: CDP-13 DNA of S. marcecens isolated from inoculated plant).