Influence of hypergravity on root growth phenotype and physio-biochemical parameters in sorghum (Sorghum bicolor L.)

I, Mahamed Ashiq; Honnutagi, Sana B; Hosamani, Ravikumar; B, Deepthi R; Swamy, Basavalingayya K; Sathasivam, Malarvizhi; Bagewadi, Basavaraj; Reddy, Uday G.; G Hanamaratti, N.

Influence of hypergravity on root growth phenotype and physio-biochemical parameters in sorghum (Sorghum bicolor L.)

Volume 12 (2024): Issue 1 (January 2024)

By:

Mahamed Ashiq I, Sana B Honnutagi, Ravikumar Hosamani, Deepthi R B, Basavalingayya K Swamy, Malarvizhi Sathasivam, Basavaraj Bagewadi, Uday G. Reddy and N. G Hanamaratti

Open Access

|Dec 2024

Figures & Tables

The study evaluated different levels of hypergravity intensities on root, shoot, and seedling vigor index of sorghum seedlings under laboratory conditions using the between-paper method. (a) Visual representation of qualitative root and shoot phenotype responses to 20, 40, 80, 100, 250, 500, 1000, 2500, and 5000-times gravity (g) for a set period of one hour was provided. (b) Variability (shown in red box plot) in the shoot length phenotype among the ten treatments was analyzed. (c) Variability (shown in green box plot) among the ten treatments for root length phenotype was examined. (d) Variability (shown in orange box plot) among the 10 treatments for total seedling length. (e) Variability (illustrated in pink box plot) in the seedling vigor index among the ten treatments was also analyzed. In each test group, 30 seedlings were utilized in triplicates, and such four independent experiments were employed for statistical analysis. The resultant data underwent one-way ANOVA using SPSS – version 20.00. Statistical significance * (p ≤ 0.05), ** (p ≤ 0.01), *** (p ≤ 0.001).

The varied response observed among different sorghum genotypes to hypergravity was examined in laboratory conditions using the between-paper method. (a) A qualitative depiction of hypergravity-induced (1000g, 1 hr) increased root and shoot length phenotypes at the seedling stage were documented on the final count (10th day) of nine different genotypes of sorghum seedlings. Hypergravity-induced alterations in shoot length (b), root length (c), and seedling vigor index (d) of different genotypes of sorghum seedlings were analyzed. The resultant data underwent an independent sample t-test [N=360] using SPSS – version 20.00. Statistical significance * (p ≤ 0.05), ** (p ≤ 0.01), *** (p ≤ 0.001).

Changes in seedling growth characteristics of three selected sorghum genotypes were examined under greenhouse conditions. (a) A hypergravity-induced (1000g, 1 hr) enhanced seedling growth phenotype was recorded at the seedling growth stage (10th day) of sorghum grown in a greenhouse. Hypergravity-induced changes in shoot length (b), root length (c), seedling vigor index (d), seedling fresh weight (e), and seedling dry weight (f) of selected genotypes of sorghum seedlings were analyzed. The resultant data underwent an independent sample t-test [N=96] using SPSS – version 20.00. Statistical significance * (p ≤ 0.05), ** (p ≤ 0.01), *** (p ≤ 0.001).

(a) Phenotypic changes were observed at the 55-day-old vegetative growth stage of three selected sorghum genotypes under greenhouse conditions. (b) Hypergravity-induced alterations in root length, (c) root volume, (d) root fresh weight, (e) root dry weight, and (f) secondary roots were analyzed. (g) Hypergravity-induced alterations in shoot length, and (h) shoot dry weight were also assessed. The resultant data underwent an independent sample t-test [N=48] using SPSS – version 20.00. Statistical significance * (p ≤ 0.05), ** (p ≤ 0.01), *** (p ≤ 0.001).

Hypergravity induces dynamic changes in phytohormone levels in the roots of sorghum seedlings, as profiled on the 10th day after exposure. The resultant data underwent an independent sample t-test using SPSS – version 20.00. Statistical significance * (p ≤ 0.05), ** (p ≤ 0.01), *** (p ≤ 0.001).

Qualitative image of nine different sorghum genotypes used for this study.

This experiment was grouped as below. Statistical superiority was identified using an independent ‘t’ test comparing control with hypergravity treatment.

Response of different sorghum genotypes to hypergravity under laboratory conditions using between-paper-method_ Hypergravity-induced changes in germination, root, length, shoot, and seedling vigor index in different genotypes of sorghum seedlings were recorded on the final count (day 10) of 9 different genotypes of sorghum seedlings_ Resultant data was subjected to an independent sample t-test (four independent experimental groups of 30 seedlings in triplicate (30×3 = 90; 90×4 experiments = 360)) using SPSS – version 20_00_

Genotypes	Ctr (1g) Mean ± SEM	1000g 1 hr Mean ± SEM	% change over control	p-value	t-stat.
Germination (%)
SPV2217	91.5 ± 2.33	92.25 ± 2.18	0.82	0.835	0.313
DSV4	89.50 ± 1.45	90.50 ± 1.20	1.12	0.869	0.177
M35-1	94.50 ± 1.33	93.75 ± 1.66	−0.79	0.665	0.469
SVD1418R	89.50 ± 2.72	91.50 ± 1.85	2.23	0.709	0.404
KODMURKI LOCAL	93.50 ± 1.52	90.50 ± 3.84	−3.21	0.571	0.645
IS18551	91.50 ± 1.52	90.50 ± 2.33	−1.09	0.713	0.397
SVD1358R	91.25 ± 1.52	94.50 ± 1.33	3.56	0.812	0.981
LAKMAPUR LOCAL	93.75 ± 1.66	89.50 ± 2.72	−4.53	0.382	0.548
CSV 29R	91.50 ± 1.85	93.50 ± 1.52	2.19	0.617	0.261
Shoot length (cm)
SPV2217	10.56 ± 0.70	12.13 ± 0.83	14.92	0.046	4.51
DSV4	14.38 ± 0.43	14.69 ± 0.45	2.16	0.59	0.59
M35-1	12.38 ± 0.44	14.38 ± 0.74	16.16	0.039	5.66
SVD1418R	13.65 ± 0.38	13.78 ± 0.35	0.92	0.61	0.56
KODMURKI LOCAL	13.10 ± 0.55	13.37 ± 0.86	2.02	0.32	1.17
IS18551	11.75 ± 0.27	12.12 ± 0.21	3.13	0.19	3.33
SVD1358R	11.67 ± 0.36	11.80 ± 0.73	1.16	0.42	0.94
LAKMAPUR LOCAL	15.33 ± 0.32	15.64 ± 0.54	2.06	0.31	3.15
CSV 29R	12.48 ± 0.78	12.62 ± 0.34	1.08	0.12	2.41
Root length (cm)
SPV2217	22.70 ± 0.80	27.58 ± 0.44	21.51	0.016	4.86
DSV4	18.34 ± 0.41	18.03 ± 0.18	−1.68	0.13	2.00
M35-1	15.57 ± 0.46	18.54 ± 1.21	19.11	0.018	6.93
SVD1418R	19.15 ± 1.09	19.19 ± 1.44	0.21	0.12	2.02
KODMURKI LOCAL	22.23 ± 0.44	22.50 ± 0.66	1.20	0.41	3.65
IS18551	18.99 ± 0.43	22.41 ± 0.60	18.00	0.030	5.25
SVD1358R	23.33 ± 0.88	23.48 ± 0.47	0.68	0.12	3.40
LAKMAPUR LOCAL	18.42 ± 0.98	18.57 ± 0.86	0.81	0.97	2.74
CSV 29R	16.51 ± 0.57	17.16 ± 1.04	3.89	0.46	3.05
Seedling vigour index (SVI)
SPV2217	3041.25 ± 39.6	3663.78 ± 26.4	20.47	0.005	4.86
DSV4	2929.11 ± 60.4	2961.63 ± 51.4	1.11	0.70	1.93
M35-1	2640.16 ± 36.9	3085.71 ± 19.4	16.88	0.006	5.995
SVD1418R	2935.45 ± 13.1	3015.69 ± 18.6	2.73	0.12	5.19
KODMURKI LOCAL	3303.27 ± 52.4	3245.50 ± 53.5	−1.75	0.47	1.42
IS18551	2812.62 ± 36.3	3124.33 ± 25.7	11.08	0.01	4.355
SVD1358R	3192.92 ± 22.3	3333.96 ± 21.6	4.42	0.09	2.61
LAKMAPUR LOCAL	3163.19 ± 27.6	3061.30 ± 20.4	−3.22	0.13	3.90
CSV 29R	2652.75 ± 15.8	2785.28 ± 25.7	3.75	0.16	5.28
Total Seedling length (cm)
SPV2217	33.26 ± 0.56	39.72 ± 0.21	20.47	0.005	4.86
DSV4	32.72 ± 0.16	32.73 ± 0.09	1.11	0.70	1.93
M35-1	27.94 ± 0.22	32.92 ± 0.14	16.88	0.006	5.995
SVD1418R	32.80 ± 0.14	32.97 ± 0.30	2.73	0.12	5.19
KODMURKI LOCAL	35.33 ± 0.22	35.87 ± 0.25	−1.75	0.47	1.42
IS18551	30.74 ± 0.39	34.53 ± 0.12	11.08	0.001	4.355
SVD1358R	34.99 ± 0.19	35.28 ± 0.28	4.42	0.09	2.61
LAKMAPUR LOCAL	33.74 ± 0.25	34.20 ± 0.17	−3.22	0.13	3.90
CSV 29R	29.00 ± 0.49	29.78 ± 0.66	3.75	0.16	5.28

Changes in germination, root, and shoot growth characteristics of three selected sorghum genotypes under greenhouse conditions_ Hypergravity-induced changes in germination (%), root length (cm), root volume (cm3), root fresh weight (gm), root dry weight (gm), number of secondary roots of selected genotypes of sorghum in greenhouse conditions recorded at the beginning of the reproductive phase (55th-day) of sorghum grown in a greenhouse_ The resultant data was subjected to an independent sample t-test [N=48] using SPSS – version 20_00_

Genotypes	Ctr (1g) Mean ± SEM	1000g 1 hr Mean ± SEM	% change over control	p-value	t-stat.
Germination (%)
M35-1	94.5 ± 1.33	95.0 ± 1.66	0.53	0.566	0.469
SPV2217	93.8 ± 1.52	94.0 ± 3.84	0.27	0.179	0.645
IS18551	91.5 ± 1.52	93.0 ± 2.33	1.64	0.492	0.397
Root length (cm)
M35-1	64.9 ± 0.59	77.5 ± 0.96	19.33	0.011	13.41
SPV2217	155.0 ± 1.01	180.7 ± 0.98	16.62	0.015	13.88
IS18551	103.0 ± 0.85	87.1 ± 0.35	−18.25	0.012	24.39
Root volume (cm³)
M35-1	36.6 ± 3.96	43.0 ± 2.34	17.42	0.026	2.927
SPV2217	76.7 ± 1.10	88.0 ± 2.52	14.67	0.025	2.964
IS18551	43.6 ± 2.95	41.2 ± 1.11	−5.45	0.011	9.571
Root fresh weight (gm)
M35-1	65.4 ± 0.86	71.3 ± 0.55	18.19	0.01	11.32
SPV2217	69.0 ± 0.58	79.4 ± 0.98	15.08	0.015	12.43
IS18551	72.2 ± 0.54	61.2 ± 0.32	−7.09	0.011	9.85
Root dry weight (gm)
M35-1	8.3 ± 1.35	9.3 ± 3.28	12.35	0.003	4.32
SPV2217	11.7 ± 2.71	12.3 ± 2.87	4.91	0.202	5.17
IS18551	10.0 ± 1.49	10.1 ± 2.16	0.05	0.157	4.78
Number of secondary roots
M35-1	15.8 ± 1.58	20.8 ± 4.71	16.90	0.014	4.431
SPV2217	23.8 ± 1.83	25.5 ± 3.93	10.87	0.017	3.274
IS18551	23.3 ± 1.65	22.5 ± 1.47	−3.23	0.063	2.967
Shoot length (cm)
M35-1	115.3 ± 7.2	129.5 ± 7.69	12.36	0.025	4.333
SPV2217	212.0 ± 13.5	235.0 ± 12.9	10.85	0.016	7.534
IS18551	164.0 ± 10.5	169.5 ± 17.2	3.35	0.059	9.532
Number of leaves per plant
M35-1	09 ± 0.40	9.3 ± 0.51	2.78	0.134	1.732
SPV2217	11 ± 0.40	11.3 ± 0.54	2.27	0.235	1.543
IS18551	13 ± 0.86	13.5 ± 0.12	3.85	0.323	1.786
Shoot fresh weight (gm)
M35-1	151.6 ± 1.9	163.2 ± 1.3	7.65	0.032	4.928
SPV2217	217.6 ± 1.7	236.4 ± 2.5	8.64	0.023	1.206
IS18551	188.6 ± 1.2	199.8 ± 3.4	5.53	0.129	2.863
Shoot dry weight (gm)
M35-1	20.6 ± 0.08	22.8 ± 0.25	10.44	0.02	5.23
SPV2217	34.9 ± 0.27	37.5 ± 0.52	7.46	0.017	7.121
IS18551	25.8 ± 0.37	26.5 ± 0.51	2.81	0.204	4.439

Physio-biochemical screening of selected sorghum genotypes_ Total chlorophyll content was quantified in leaf tissue; EC and TDH activity were quantified in seeds; catalase and SOD enzyme activities were quantified in seedlings_ All biochemical assays were carried out in three replications and four independent experiments were used for an independent variable ‘T’ test analysis using SPSS – version 20_00 (T–tab_ 4_303)

Genotypes/parameters	Ctr (1g)	1000g 1 hr.	% change over control	p-value	t-stat.

	Mean ± SEM	Mean ± SEM
Total chlorophyll content (mg g⁻¹ of tissue)
M35-1	2.20 ± 0.19	2.76 ± 0.04	25.87	0.017^*	5.68
SPV2217	2.36 ± 0.07	2.67 ± 0.09	13.13	0.038^*	4.80
IS18551	2.70 ± 0.11	3.05 ± 0.08	12.19	0.023^*	8.87
Electrical conductivity (dS/m)
M35–1	0.29 ± 0.003	0.28 ± 0.080	−2.55	0.538 ^NS	0.70
SPV2217	0.36 ± 0.010	0.33 ± 0.005	−10.23	0.113 ^NS	2.34
IS18551	0.23 ± 0.010	0.21 ± 0.005	−10.56	0.221 ^NS	1.54
Total dehydrogenase (TDH)
M35-1	0.73 ± 0.02	0.89 ± 0.01	21.91	0.010^*	8.80
SPV2217	0.74 ± 0.05	0.86 ± 0.03	16.87	0.030^*	6.19
IS18551	0.81 ± 0.08	0.92 ± 0.05	14.71	0.020^*	9.20
Catalase (U/ml of enzyme) of genotype M35-1
Root	5.867 ± 0.057	7.32 ± 0.168	24.76	0.008^*	8.18
Shoot	5.65 ± 0.172	6.03 ± 0.245	6.72	0.282^NS	1.26
Superoxide dismutase (SOD) (U/ml of enzyme) of genotype M35-1
Root	1.41 ± 0.40	1.75 ± 0.071	24.11	0.023^*	4.30
Shoot	2.08 ± 0.043	2.13 ± 0.08	2.4	0.589 ^NS	0.60

Hypergravity elicits robust phytohormone dynamics in the root, profiled on the final count (day 10) of sorghum seedlings_ Resultant data was subjected to an independent sample t-test using SPSS – version 20_00_

Hormones	Phytohormones (ng/gm of tissue)
Hormones	Ctr (1g) Mean ± SEM	1000g 1 hr. Mean ±SEM	% change over control	p-value	t-stat.
Indole Acetic Acid (IAA)	131 ± 1.54	179 ± 7.33	36.59	0.019	6.396
Indole Butyric Acid (IBA)	23.20 ± 0.39	41.81 ± 0.29	80.18	0.000	38.18
Benzyl aminopurine (BAP)	0.61 ± 0.03	0.54 ± 0.03	−10.30	0.271	1.278
Zeatin transe isomer	28.05 ± 0.68	2.58 ± 0.09	−90.81	0.001	37.12
Trans zeatin Riboside (ZR)	0.31 ± 0.02	0.40 ± 0.03	30.66	0.084	2.603
Gibberellic Acid 7 (GA7)	0.07 ± 0.00	0.05 ± 0.00	−21.51	0.058	2.858
Gibberellic Acid 4 (GA4)	3.13 ± 0.13	1.52 ± 0.09	−51.61	0.001	10.11
Gibberellic Acid 3 (GA3)	0.93 ± 0.03	0.41 ± 0.02	−55.75	0.000	15.30
Abscisic Acid (ABA)	2.37 ± 0.03	1.81 ± 0.06	−23.40	0.005	7.506
Salicylic Acid (SA)	1046 ± 22.06	1650 ± 46.16	57.73	0.002	11.80
Cis-Jasmonate (cis-JA)	22.35 ± 0.95	29.27 ±0.26	30.92	0.014	6.992
Methyl-Jasmonate	0.47 ± 0.01	0.87 ± 0.01	87.13	0.000	17.71

Changes in germination, root, and shoot growth characteristics of three selected sorghum genotypes under greenhouse conditions_ Hypergravity-induced (1000xg, 1 hr) changes in germination, root length (cm), shoot length (cm), seedling vigour index, seedling fresh weight (gm), seedling dry weight (gm) and phenotype recorded at seedling growth stage (10th-day) of sorghum grown in a greenhouse condition_ The resultant data was subjected to an independent sample t-test [N=96] using SPSS – version 20_00_

Genotypes	Ctr (1g) Mean ± SEM	1000g 1 hr Mean ± SEM	% change over control	p-value	t-stat.
Germination (%)
M35-1	87.8 ± 2.51	89.5 ± 1.15	1.99	0.145	0.361
SPV2217	96.5 ± 0.00	93.0 ± 2.33	−3.63	0.116	0.11
IS18551	93.5 ± 0.66	94.3 ± 3.00	0.80	0.139	0.108
Root length (cm)
M35-1	16.1 ± 0.46	18.5 ± 1.02	15.06	0.010	6.072
SPV2217	15.4 ± 0.82	17.5 ± 0.58	13.61	0.039	4.729
IS18551	16.7 ± 0.45	17.1 ± 0.27	2.55	0.138	1.961
Shoot length (cm)
M35-1	8.8 ± 0.41	10.0 ± 1.35	14.57	0.043	4.868
SPV2217	8.5 ± 1.44	9.4 ± 0.56	10.95	0.036	4.290
IS18551	10.1 ± 0.28	10.3 ± 0.95	1.49	0.079	5.307
Seedling vigour index (SVI)
M35-1	2195.1 ± 24.4	2558.8 ± 20.9	16.57	0.005	5.251
SPV2217	2422.0 ± 34.1	2662.7 ± 24.7	9.94	0.029	2.325
IS18551	2635.8 ± 29.9	2751.4 ± 33.4	4.39	0.074	1.504
Seedling fresh weight (gm)
M35-1	9.2 ± 0.25	10.4 ± 0.71	13.93	0.039	2.293
SPV2217	11.2 ± 0.52	12.3 ± 0.70	10.54	0.035	2.56
IS18551	10.6 ± 0.18	11.1 ± 0.23	5.20	0.053	2.527
Seedling dry weight (gm)
M35-1	1.29 ± 0.52	1.49 ± 0.60	15.56	0.028	0.293
SPV2217	1.88 ± 0.30	2.10 ± 0.48	12.00	0.034	0.644
IS18551	1.41 ± 0.35	1.47 ± 0.47	4.79	0.138	0.284

Seed Diameter and 100 Seed Weight Across Different Sorghum Genotypes_

Sl. No.	Sorghum Genotypes	Seed Diameter (mm)	100 Seed Weight (g)
1	SVD1418R	1.6	3.85
2	IS18551	1.3	2.67
3	SVD1358R	1.4	4.34
4	DSV4	1.5	3.55
5	LAKMAPUR LOCAL	1.5	3.10
6	SPV2217	1.6	4.15
7	M35-1	1.6	4.16
8	CSV 29R	1.5	3.52
9	KODMURKI LOCAL	1.4	3.35

Varied hypergravity intensities evaluated for root, shoot, and seedling vigor index of sorghum seedlings in laboratory conditions_ In each test group (Control, 20, 40, 80, 100, 250, 500, 1000, 2500 and 5000g), four independent experimental groups of 30 seedlings in triplicate (30×3 = 90; 90×4 experiments = 360) were used for statistical analysis_ Resultant data was subjected to one-way ANOVA using SPSS – version 20_00_

Hyper g treatment	Mean ± SEM	% change over control	p-value	Cal. F	CD (5 %)	CV (%)
Germination (%)
Ctr (1g)	90.75±0.85	-	-	4.20	3.15	2.37
20g 1 hr	90.75±1.43	0.00	1.000
40g 1 hr	90.75±1.25	0.00	1.000
80g 1 hr	94.75±0.25	4.41	0.221
100g 1 hr	87.75±0.25	−3.31	0.592
250g 1 hr	89.75±0.25	−1.10	0.999
500g 1 hr	92.5±0.64	1.93	0.970
1000g 1 hr	94.75±1.25	4.41	0.221
2500g 1 hr	91.5±1.71	0.83	1.000
5000g 1 hr	93.5±1.26	3.03	0.699
Shoot length (cm)
Ctr (1g)	12.52±0.04	-	-	41.92	0.43	2.26
20g 1 hr	12.96±0.08	3.51	0.491
40g 1 hr	11.77±0.04	−5.99	0.024
80g 1 hr	12.99±0.12	3.77	0.394
100g 1 hr	13.28±0.04	6.07	0.211
250g 1 hr	13.07±0.08	4.43	0.200
500g 1 hr	12.47±0.05	−0.34	1.000
1000g 1 hr	15.32±0.17	22.38	0.011
2500g 1 hr	12.27±0.07	−2.00	0.959
5000g 1 hr	13.29±0.03	6.15	0.239
Root length (cm)
Ctr (1g)	19.53±0.35	-	-	15.67	1.08	3.61
20g 1 hr	21.56±0.37	6.58	0.230
40g 1 hr	21.17±0.39	8.42	0.101
80g 1 hr	19.71±0.26	0.92	1.000
100g 1 hr	20.05±0.44	2.70	0.992
250g 1 hr	19.59±0.64	0.31	1.000
500g 1 hr	19.03±0.54	−2.56	0.994
1000g 1 hr	23.97±0.31	22.75	0.023
2500g 1 hr	19.61±0.34	0.41	1.000
5000g 1 hr	20.95±0.27	7.30	0.247
Seedling vigour index
Ctr (1g)	2918.0±22.13	-	-	22.35	138.94	3.15
20g 1 hr	3043.0±41.23	4.28	0.171
40g 1 hr	2914.7±7.57	−0.11	1.000
80g 1 hr	3099.5±35.74	6.22	0.063
100g 1 hr	2850.7±40.23	−2.30	0.973
250g 1 hr	2980.5±20.43	2.14	0.974
500g 1 hr	2963.7±40.38	1.57	1.000
1000g 1 hr	3638.7±58.45	24.70	0.001
2500g 1 hr	2906.7±37.45	−0.39	1.000
5000g 1 hr	3117.7±27.98	6.85	0.059

DOI: https://doi.org/10.2478/gsr-2024-0013 | Journal eISSN: 2332-7774

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Language: English

Page range: 177 - 197

Published on: Dec 31, 2024

Published by: American Society for Gravitational and Space Research

In partnership with: Paradigm Publishing Services

Publication frequency: 2 times per year

Keywords:

Hypergravity,

Sorghum,

Root phenotype,

Physio-biochemical parameters

Related subjects:

Life sciences,

Life sciences, other,

Materials sciences,

Materials sciences, other,

Physics,

Physics, other

© 2024 Mahamed Ashiq I, Sana B Honnutagi, Ravikumar Hosamani, Deepthi R B, Basavalingayya K Swamy, Malarvizhi Sathasivam, Basavaraj Bagewadi, Uday G. Reddy, N. G Hanamaratti, published by American Society for Gravitational and Space Research
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Previous article Volume 12 (2024): Issue 1 (January 2024)

Influence of hypergravity on root growth phenotype and physio-biochemical parameters in sorghum (Sorghum bicolor L.)

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Figure 2.

Figure 3.

Figure 4.

Figure 5.

Figure 6.

Supplementary Figure 1.

Hypergravity elicits robust phytohormone dynamics in the root, profiled on the final count (day 10) of sorghum seedlings_ Resultant data was subjected to an independent sample t-test using SPSS – version 20_00_

Seed Diameter and 100 Seed Weight Across Different Sorghum Genotypes_

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