Aspergillus niger boosted heat stress tolerance in sunflower and soybean via regulating their metabolic and antioxidant system

Figures & data

Table 1. Effect of A. niger filtrate on the growth of rice seedlings.

Growth attributes	Control (DW)	Control (Czk)	A. niger
Shoot Length (cm)	12.2 ± .35^a	13.4 ± .24^ab	14.97 ± .32^ab
Root Length (cm)	6.1 ± .28^a	6.4 ± .28^ab	7.8 ± .25^b
Fresh Weight Shoot (g)	0.034 ± .02^a	0.042 ± .01^b	0.047 ± .01^b
Fresh Weight Root (g)	0.094 ± .06^a	0.097 ± .05^a	0.157 ± .01^b
Dry Weight Shoot (g)	0.0054 ± .01^a	0.0059 ± .03^a	0.0077 ± .04^b
Dry Weight Root (g)	0.0157 ± .01^a	0.0165 ± .04^a	0.0191 ± .04^b
Chlorophyl (SPAD)	21.71 ± 0.5^a	22.9 ± 0.36^b	25.6 ± 0.28^c

Czk = Czapek medium, DW = Distilled water. Data are means of 3 replicates with ±standard error. The data in each row followed by different letters in superscript are significantly different (p < 0.05) from each other as estimated by Duncan's Multiple Range Test (DMRT).

Figure 1. Phylogenetic tree construction (using 12 taxa, 11 reference and 1 clone) for the molecular identification of isolate SonchL-7 using neighbor joining (NJ) method. 49% bootstrap value confirmed isolate SonchL-7 as A. niger.

Table 2. Effect of A. niger on the growth of sunflower seedlings.

Growth attributes/ temperature stress	25°C		40°C
	Control	A. niger	Control	A. niger
Total Chlorophyl (SPAD)	31.4 ± 2.35^a	43.4 ± 2.12^b	32 ± 1.14^a	33.9 ± 02^a
Shoot Length (cm)	25.5 ± 0.35^c	29 ± 0.67^d	19.5 ± 0.28^a	22.83 ± 0.6^b
Root Length (cm)	9 ± 0.28^b	15 ± 0.35^c	6 ± 0.58^a	8.13 ± 0.59^b
Fresh Weight Shoot (g)	1.2 ± 0.19^a	1.7 ± 0.25^b	1.06 ± 0.04^a	1.09 ± 0.14^a
Fresh Weight Root (g)	0.178 ± 0.05^b	0.34 ± 0.08^c	0.017 ± 0.07^a	0.021 ± 0.12^a
Dry Weight Shoot (g)	0.085 ± 0.06^b	0.102 ± 0.05^c	0.04 ± 0.009^a	0.052 ± 0.01^a
Dry Weight Root (g)	0.024 ± 0.06^a	0.032 ± 0.01^b	0.018 ± 0.01^a	0.027 ± 0.06^b

The data presented are mean of 3 replicates with ±standard error. The data in each row followed by different letters different letters in superscript are significantly different (p < 0.05) from each other as estimated by Duncan's Multiple Range Test (DMRT).

Table 3. Effect of A. niger on the growth of soybean seedlings.

Growth attributes/ temperature stress	25°C		40°C
	Control	A. niger	Control	A. niger
Total Chlorophyl (SPAD)	30.13 ± 0.16^a	34.27 ± 1.31^a	29.13 ± 1.3^a	32.03 ± 1.5^a
Shoot Length (cm)	38.27 ± 1.36^b	47.47 ± 0.28^c	26 ± 0.8^a	34.4 ± 1.4^b
Root Length (cm)	16.13 ± 3.08^b	18 ± 0.38^c	10 ± 0.5^a	13.3 ± 0.7^b
Fresh Weight Shoot (g)	1.13 ± 0.12^a	1.24 ± 0.1^a	0.82 ± 0.3^a	1.21 ± 0.3^a
Fresh Weight Root (g)	0.18 ± 0.14^b	0.22 ± 0.17^c	0.13 ± 0.2^a	0.16 ± 0.4^b
Dry Weight Shoot (g)	0.135 ± 0.11^b	0.143 ± 0.07^b	0.079 ± 0.3^a	0.083 ± 0.3^a
Dry Weight Root (g)	0.075 ± 0.02^b	0.102 ± 0.06^c	0.012 ± 0.1^a	0.014 ± 0.1^a

The data presented are mean of 3 replicates with ±standard error. The data in each row followed by different letters different letters in superscript are significantly different (p < 0.05) from each other as estimated by Duncan's Multiple Range Test (DMRT).

Figure 2. (A) Hydrogen peroxide (H₂O₂) and (B) lipid peroxidation (MDA) B in soybean or sunflower seedlings grown at 25°C and 40°C inoculated with and without A. niger. Data represent mean of biological triplicates. Similar bars labeled with different letters are significantly different (p < 0.05) as estimated by Duncan’s Multiple Range Test (DMRT).

Figure 3. (A) Total proline and (B) phenolics in soybean or sunflower seedlings grown at 25°C and 40°C inoculated with and without A. niger. Data represent mean of biological triplicates. Similar bars labeled with different letters are significantly different (p < 0.05) as estimated by Duncan’s Multiple Range Test (DMRT).

Figure 4. Activity of (A) CAT; (B) POD; (C) AAO; (D) SOD and (E) GSH in soybean or sunflower seedlings grown at 25°C and 40°C inoculated with and without A. niger. Data represent mean of biological triplicates. Similar bars labeled with different letters are significantly different (p < 0.05) as estimated by Duncan’s Multiple Range Test (DMRT).

Figure 5. GC MS analysis of ABA content of soybean or sunflower seedlings grown at 25°C and 40°C inoculated with and without A. niger. Data represent mean of biological triplicates. Similar bars labeled with different letters are significantly different (p < 0.05) as estimated by Duncan’s Multiple Range Test (DMRT).

Figure 6. Analysis of total lipids (A), proteins (B) and soluble sugars (C) of soybean or sunflower seedlings grown at 25°C and 40°C inoculated with and without A. niger. Data represent mean of biological triplicates. Similar bars labeled with different letters are significantly different (p < 0.05) as estimated by Duncan’s Multiple Range Test (DMRT).