Potassium Fertilization Stimulates Sucrose-to-Starch Conversion and Root Formation in Sweet Potato (Ipomoea batatas (L.) Lam.)
Abstract
:1. Introduction
2. Results
2.1. Photosynthetic Parameters in Sweet Potato Leaves under Different K2O Rates
2.2. Dynamic Accumulation and Simulation of Sweet Potato Biomass
2.3. Distribution of Sweet Potato Biomass
2.4. Yield Components
2.5. Changes of Sucrose and Starch Content in SPSR
2.6. Enzyme Activities Involved in the Sucrose–Starch Metabolism in SPSR
2.7. Genes Transcription Involved in the Sucrose–Starch Metabolism in SPSR
2.8. Relationship Between Enzyme Activities Related to Sucrose and Starch with Starch Accumulation and Storage Root Yield
3. Discussion
3.1. Plant Growth, Biomass Accumulation and Distribution in SPSR was Improved by Appropriate K Application
3.2. Appropriate K Application Is Beneficial to Sucrose-to-Starch Conversion in SPSR
4. Materials and Methods
4.1. Experimental Design
4.2. Sampling and Processing
4.3. Leaf Photosynthesis Parameters
4.4. Sucrose and Starch Analysis
4.5. Sucrose–Starch Metabolizing Enzymatic Extraction and Analysis
4.6. RNA Extraction and Gene Transcriptional Analysis in SPSR
4.7. Weather Data and Statistical Analysis
5. Conclusions
- 1)
- Compared to the no-K treatment, sweet potato yield was remarkably improved by K application, although treatments at high levels of K, i.e., 375 kg K2O ha−1, significantly decreased storage root yield. K application enhanced biomass accumulation of plant and storage root yield by promoting VT and T.
- 2)
- K application enhanced the photosynthetic capacity of sweet potato at 35 DAT and 55 DAT, accompanied with an increased storage root weight. The reduction of Pn induced by K deficiency was mainly caused by stomatal limitation at 35 DAT and by non-stomatal factors at 55 DAT.
- 3)
- K application promoted the starch accumulation mainly by improving the activities of SuSy, AGPase and SSS, and these genes’ transcriptions, and AGPase is the speed-limiting enzyme for the synthesis of starch in SPSR of the K-treated treatments.
- 4)
- Future research is required to determine the correlation of K + transport activity in root and K tolerance in sweet potato, in order to breed low-K-tolerant sweet potato cultivars in the future.
Supplementary Materials
Author Contributions
Funding
Data Availability Statement
Acknowledgments
Conflicts of Interest
References
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Cultivar | K2O Rate (kg ha−1) | Pn (μmol CO2 m−2 s−1) | gs (mol H2O m−2 s−1) | Ci (μmol CO2 mol−1) | Non-Ls | Ls | |||||
---|---|---|---|---|---|---|---|---|---|---|---|
35 DAT | 55 DAT | 35 DAT | 55 DAT | 35 DAT | 55 DAT | 35 DAT | 55 DAT | 35 DAT | 55 DAT | ||
2017 | |||||||||||
Xushu 32 | 0 | 30.85 ab | 28.3 b | 0.63 d | 0.72 b | 321.9 bc | 339.9 a | 514.6 a | 471.9 ab | 0.16 a | 0.12 bc |
75 | 31.14 ab | 29.16 ab | 0.69 cd | 0.77 ab | 325.2 b | 330.5 bc | 473.2 ab | 431.8 bc | 0.13 b | 0.11 abc | |
150 | 31.59 a | 29.13 ab | 0.73 bc | 0.89 a | 328.4 a | 327.9 c | 449.6 bc | 366.9 c | 0.14 b | 0.1 c | |
225 | 30.98 ab | 30.29 a | 0.82 a | 0.79 ab | 323.2 bc | 332.3 bc | 397.6 c | 435.5 abc | 0.16 a | 0.11 abc | |
300 | 30.34 b | 29.85 a | 0.78 ab | 0.69 b | 322.3 bc | 335.2 ab | 414.3 c | 492.6 ab | 0.14 ab | 0.11 ab | |
375 | 28.11 c | 29.95 a | 0.73 bc | 0.63 b | 320.7 c | 332.7 bc | 442.8 bc | 533 a | 0.15 ab | 0.11 a | |
CV across K2 O rate (%) | 3.71 | 2.25 | 8.25 | 10.91 | 0.78 | 1.13 | 8.52 | 11.51 | 7.65 | 4.62 | |
Ningzishu 1 | 0 | 30.97 b | 27.94 c | 0.69 bc | 0.49 b | 319.6 c | 338.7 b | 472.8 ab | 699.7 a | 0.17 a | 0.12 ab |
75 | 31.09 b | 31.24 a | 0.8 a | 0.79 a | 326.3 b | 330 b | 407.6 b | 422 b | 0.15 b | 0.11 bc | |
150 | 33.96 a | 30.79 ab | 0.83 a | 0.8 a | 332.1 a | 327.5 b | 402.5 b | 424.4 b | 0.14 b | 0.11 bc | |
225 | 31.46 b | 30.14 ab | 0.77 ab | 0.75 a | 325 b | 332.6 b | 422.1 b | 448.1 b | 0.15 ab | 0.1 c | |
300 | 29.23 c | 29.5 b | 0.65 c | 0.69 a | 325.1 b | 340.3 a | 509 a | 502.7 b | 0.14 b | 0.1 c | |
375 | 29.38 c | 30.14 ab | 0.63 c | 0.48 b | 318.1 c | 330.8 b | 505.2 a | 703.7 a | 0.13 b | 0.13 a | |
CV across K2O rate (%) | 5.05 | 3.52 | 10.32 | 19.82 | 1.41 | 1.26 | 9.79 | 22.13 | 9.00 | 9.28 | |
Analysis of variance | Cultivar (C) | * | * | ns | ** | ns | ns | ns | ** | ns | ns |
K2O rate (K) | ** | ** | ** | ** | ** | ** | ** | ** | ** | ** | |
C × K | ** | * | ** | ns | ns | * | ** | * | ns | ** | |
2018 | |||||||||||
Xushu 32 | 0 | 27.77 bc | 18.96 b | 0.76 ab | 0.69 bc | 297.69 a | 309.6 ab | 399.4 abc | 455.9 ab | 0.18 b | 0.18 a |
75 | 29.84 ab | 19.15 b | 0.76 ab | 0.75 abc | 299.69 a | 300.8 ab | 396.3 bc | 411.3 abc | 0.17 ab | 0.17 a | |
150 | 31.21 a | 21.85 a | 0.83 a | 0.84 a | 301.2 a | 294.5 b | 365.2 c | 353.4 c | 0.17 a | 0.19 a | |
225 | 28.12 bc | 21.19 a | 0.64 b | 0.79 ab | 304 a | 296.5 ab | 477.8 ab | 376.1 bc | 0.16 ab | 0.16 a | |
300 | 26.16 c | 21.91 a | 0.62 b | 0.7 bc | 301.1 a | 294.4 b | 500.3 a | 426.2 abc | 0.17 ab | 0.19 a | |
375 | 26.49 c | 20.46 ab | 0.6 b | 0.65 c | 300 a | 294.3 b | 500.7 a | 458.8 a | 0.16 ab | 0.19 a | |
CV across K2 O rate (%) | 6.30 | 5.75 | 12.14 | 8.93 | 0.92 | 1.85 | 12.02 | 9.37 | 4.80 | 8.17 | |
Ningzishu 1 | 0 | 27.1 b | 20.86 c | 0.47 bc | 0.46 b | 281.75 c | 292.7 a | 607.6 ab | 646.5 a | 0.23 a | 0.25 b |
75 | 29 ab | 24.98 ab | 0.5 bc | 0.55 ab | 293.73 bc | 283.1 ab | 589.3 ab | 520 ab | 0.18 b | 0.24 b | |
150 | 29.45 a | 26.05 a | 0.72 a | 0.61 a | 300.5 ab | 283.7 ab | 420.3 c | 466.6 b | 0.17 bc | 0.23 b | |
225 | 27.45 ab | 22.67 bc | 0.57 b | 0.55 ab | 310 a | 291.5 ab | 547.1 b | 548.4 ab | 0.14 c | 0.21 b | |
300 | 25.11 c | 21.99 c | 0.45 c | 0.45 b | 305.6 ab | 279.6 bc | 689.2 a | 633.2 a | 0.18 b | 0.29 a | |
375 | 23.96 c | 22.53 bc | 0.48 bc | 0.44 b | 297.8 ab | 270.3 c | 630.5 ab | 630 a | 0.16 bc | 0.22b | |
CV across K2O rate (%) | 7.25 | 7.66 | 17.41 | 12.61 | 3.03 | 2.65 | 14.39 | 11.69 | 15.49 | 11.68 | |
Analysis of variance | Cultivar (C) | ** | ** | ** | ** | ns | ** | ** | ** | * | ** |
K2O rate (K) | ** | ** | ** | ** | * | ** | ** | ** | ** | ** | |
C × K | ns | * | ns | ns | ** | ns | ns | ns | ** | ns |
K2O Rate (kg ha−1) | 2017 | 2018 | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
Equations | r | Tm (d) | T (d) | VT (g d−1) | Equations | r | Tma (d) | T (d) | VT (g d−1) | |
Xushu 32 | ||||||||||
0 | y = 157.10/(1 + 89.53 × 10−0.057DAT) | 0.975 ** | 78.85 | 46.21 | 1.96 | y = 165.83/(1 + 50.42 × 10−0.055DAT) | 0.991 ** | 71.28 | 47.89 | 2.00 |
75 | y = 166.40/(1 + 72.08 × 10−0.053DAT) | 0.983 ** | 80.71 | 49.69 | 1.93 | y = 187.80/(1 + 50.07 × 10−0.053DAT) | 0.979 ** | 73.84 | 49.69 | 2.18 |
150 | y = 222.81/(1 + 89.82 × 10−0.053DAT) | 0.997 ** | 84.87 | 49.69 | 2.59 | y = 213.78/(1 + 53.82 × 10−0.053DAT) | 0.997 ** | 75.20 | 49.69 | 2.48 |
225 | y = 213.52/(1 + 89.32 × 10−0.053DAT) | 0.995 ** | 84.76 | 49.69 | 2.48 | y = 212.18/(1 + 50.35 × 10−0.054DAT) | 0.993 ** | 72.57 | 48.77 | 2.51 |
300 | y = 224.31/(1 + 94.65 × 10−0.055DAT) | 0.996 ** | 82.73 | 47.89 | 2.70 | y = 231.64/(1 + 54.02 × 10−0.053DAT) | 0.999 ** | 75.27 | 49.69 | 2.69 |
375 | y = 199.42/(1 + 94.625 × 10−0.059DAT) | 0.980 ** | 77.12 | 44.64 | 2.58 | y = 221.99/(1 + 54.706 × 10−0.056DAT) | 0.999 ** | 71.46 | 47.03 | 2.72 |
Ningzishu 1 | ||||||||||
0 | y = 125.658/(1 + 68.704 × 10−0.059DAT) | 0.972 ** | 71.69 | 44.64 | 1.63 | y = 139.612/(1 + 51.984 × 10−0.055DAT) | 0.987 ** | 71.84 | 47.89 | 1.68 |
75 | y = 145.733/(1 + 63.953 × 10−0.056DAT) | 0.959 ** | 74.25 | 47.03 | 1.79 | y = 182.133/(1 + 55.6 × 10−0.053DAT) | 0.996 ** | 75.81 | 49.69 | 2.12 |
150 | y = 161.896/(1 + 75.734 × 10−0.055DAT) | 0.981 ** | 78.68 | 47.89 | 1.95 | y = 198.041/(1 + 53.901 × 10−0.053DAT) | 0.990 ** | 75.23 | 49.69 | 2.30 |
225 | y = 163.704/(1 + 64.517 × 10−0.056DAT) | 0.932 ** | 74.41 | 47.03 | 2.01 | y = 215.008/(1 + 39.283 × 10−0.047DAT) | 0.997 ** | 78.10 | 56.04 | 2.22 |
300 | y = 178.201/(1 + 52.325 × 10−0.051DAT) | 0.950 ** | 77.60 | 51.64 | 1.99 | y = 199.695/(1 + 49.977 × 10−0.054DAT) | 0.999 ** | 72.44 | 48.77 | 2.36 |
375 | y = 175.247/(1 + 43.939 × 10−0.054DAT) | 0.943 ** | 70.05 | 48.77 | 2.07 | y = 200.598/(1 + 46.646 × 10−0.054DAT) | 0.999 ** | 71.16 | 48.77 | 2.37 |
K2O Rate (kg ha−1) | 2017 | 2018 | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
Equations | r | Tm (d) | T (d) | VT (g d−1) | Equations | r | Tm a (d) | T (d) | VT (g d−1) | |
Xushu 32 | ||||||||||
0 | y = 656.00/(1 + 894.30 × 10−0.087DAT) | 0.985 ** | 78.12 | 30.27 | 12.51 | y = 485.20/(1 + 4269.72 × 10−0.101DAT) | 0.998 ** | 82.77 | 26.08 | 10.74 |
75 | y = 778.91/(1 + 863.84 × 10−0.085DAT) | 0.981 ** | 79.55 | 30.98 | 14.51 | y = 543.64/(1 + 2054.11 × 10−0.091DAT) | 0.989 ** | 83.82 | 28.94 | 10.84 |
150 | y = 808.98/(1 + 562.90 × 10−0.08DAT) | 0.996 ** | 79.16 | 32.92 | 14.19 | y = 597.03/(1 + 1234.96 × 10−0.085DAT) | 0.991 ** | 83.75 | 30.98 | 11.12 |
225 | y = 867.86/(1 + 590.41 × 10−0.079DAT) | 0.988 ** | 80.77 | 33.34 | 15.03 | y = 638.24/(1 + 799.19 × 10−0.079DAT) | 0.991 ** | 84.60 | 33.34 | 11.05 |
300 | y = 899.69/(1 + 562.90 × 10−0.080DAT) | 0.998 ** | 83.77 | 36.08 | 14.40 | y = 691.50/(1 + 663.53 × 10−0.078DAT) | 0.997 ** | 83.30 | 33.77 | 11.82 |
375 | y = 813.28/(1 + 471.90 × 10−0.079DAT) | 0.996 ** | 77.93 | 33.34 | 14.08 | y = 677.96/(1 + 581.241 × 10−0.08DAT) | 0.999 ** | 79.56 | 32.92 | 11.89 |
Ningzishu 1 | ||||||||||
0 | y = 518.40/(1 + 2960.94 × 10−0.095DAT) | 0.974 ** | 84.14 | 27.72 | 10.80 | y = 327.70/(1 + 3726.37 × 10−0.102DAT) | 0.995 ** | 80.62 | 25.82 | 7.33 |
75 | y = 656.52/(1 + 1830.32 × 10−0.085DAT) | 0.998 ** | 88.38 | 30.98 | 12.23 | y = 415.73/(1 + 1728.92 × 10−0.092DAT) | 0.993 ** | 81.04 | 28.63 | 8.38 |
150 | y = 761.77/(1 + 1611.56 × 10−0.082DAT) | 0.982 ** | 90.06 | 32.12 | 13.69 | y = 495.31/(1 + 672.00 × 10−0.08DAT) | 0.997 ** | 81.38 | 32.92 | 8.69 |
225 | y = 816.70/(1 + 1243.14 × 10−0.081DAT) | 0.990 ** | 87.97 | 32.51 | 14.50 | y = 542.14/(1 + 422.79 × 10−0.076DAT) | 0.999 ** | 79.56 | 34.65 | 9.03 |
300 | y = 805.13/(1 + 738.72 × 10−0.075DAT) | 0.997 ** | 88.07 | 35.12 | 13.24 | y = 510.95/(1 + 1145.07 × 10−0.094DAT) | 0.998 ** | 74.93 | 28.02 | 10.53 |
375 | y = 794.73/(1 + 1442.72 × 10−0.085DAT) | 0.996 ** | 85.58 | 30.98 | 14.81 | y = 501.24/(1 + 1165.00 × 10−0.094DAT) | 0.999 ** | 75.11 | 28.02 | 10.33 |
K2O Rate (kg K2O ha−1) | Storage Root Number (No. Plant−1) | Fresh Weight Per Storage Root (g) | Storage Root Yield (Mg ha−1) | Plant Biomass (g Per Plant) | The Biomass Rate of Storage Root/Whole Plant | |||||
---|---|---|---|---|---|---|---|---|---|---|
2017 | 2018 | 2017 | 2018 | 2017 | 2018 | 2017 | 2018 | 2017 | 2018 | |
Xushu 32 | ||||||||||
0 | 3.67 a a | 3.33 a | 163.9 e | 143.1 abc | 32.79 c | 22.18 c | 155.66 c | 155.3 c | 0.78 a | 0.80 c |
75 | 4.33 a | 4.33 a | 181.7 d | 127.4 c | 36.61 b | 25.67 bc | 160.87 bc | 170.3 bc | 0.82 a | 0.83 abc |
150 | 4.33 a | 4.33 a | 190.1 c | 140.5 bc | 38.3 ab | 28.30 ab | 187.53 a | 187.4 ab | 0.87 a | 0.85 ab |
225 | 4.33 a | 4.00 a | 200.5 b | 160.2 ab | 40.4 a | 29.79 ab | 181.88 ab | 178.3 abc | 0.87 a | 0.87 a |
300 | 4.33 a | 4.33 a | 206.8 a | 154.1 ab | 40.28 a | 31.05 a | 193.79 a | 196.9 ab | 0.88 a | 0.87 a |
375 | 4.00 a | 4.00 a | 207.8 a | 165.2 a | 38.65 ab | 30.72 ab | 184.28 ab | 202.1 a | 0.88 a | 0.82 bc |
Ningzishu 1 | ||||||||||
0 | 4.00 a | 2.33 b | 141.9 c | 148.5 a | 26.40 b | 16.11 b | 118.71 d | 120.3 c | 0.77 b | 0.71 c |
75 | 4.33 a | 3.33 ab | 162.2 b | 129.7 c | 29.58 b | 20.10 ab | 136.27 cd | 154.1 b | 0.84 a | 0.74 bc |
150 | 4.33 a | 3.67 a | 189.0 a | 132.6 bc | 34.99 a | 22.82 a | 143.78 bc | 165.0 ab | 0.85 a | 0.81 ab |
225 | 5.00 a | 4.00 a | 183.5 a | 126.2 c | 38.02 a | 24.87 a | 158.34 abc | 176.2 a | 0.86 a | 0.83 ab |
300 | 3.67 a | 3.67 a | 195.3 a | 142.4 ab | 37.95 a | 24.27 a | 165.03 ab | 175.9 a | 0.87 a | 0.85 a |
375 | 4.00 a | 3.67 a | 192.3 a | 142.5 ab | 37.31 a | 24.29 a | 167.83 a | 177.0 a | 0.87 a | 0.85 a |
Significance of factors | ||||||||||
Year | 6.594 * | 360.157 ** | 402.395 ** | 9.863 ** | 5.821 * | |||||
Cultivar (C) | ns | 34.289 ** | 78.879 ** | 78.563 ** | 6.179 * | |||||
K2O rate (K) | 2.637 * | 19.075 ** | 29.349 ** | 27.047 ** | 10.001 ** | |||||
Y × C | ns | ns | ns | ns | ns | |||||
Y × K | ns | 10.401 ** | ns | ns | ns | |||||
C × K | ns | ns | ns | ns | ns | |||||
Y × C × K | ns | 2.665 * | ns | ns | ns |
Correlation with | SPS | SuSy | AGPase | SSS | SBE |
---|---|---|---|---|---|
Starch accumulation | 0.5833 *a | 0.7208 ** | 0.5881 * | 0.5779 * | 0.7665 ** |
Storage root yield | ns | ns | 0.7992 ** | 0.7780 ** | ns |
Meteorological Data | Year | June | July | August | September | October | Total |
---|---|---|---|---|---|---|---|
Mean daily temperature (°C) | 2017 | 25.8 | 29.9 | 27.7 | 23.1 | 15.4 | 24.4 |
2018 | 27.4 | 28.8 | 28.6 | 22.8 | 16.1 | 24.7 | |
Total sunshine hours (h) | 2017 | 265.2 | 241.2 | 210.3 | 191.8 | 157.8 | 1066.3 |
2018 | 282.8 | 242.4 | 225.3 | 212.2 | 238.0 | 1200.7 | |
Total precipitation (mm) | 2017 | 92.1 | 279.9 | 105.1 | 101.6 | 75.0 | 653.7 |
2018 | 48.7 | 248.5 | 362.3 | 62.6 | 0.2 | 722.2 |
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Gao, Y.; Tang, Z.; Xia, H.; Sheng, M.; Liu, M.; Pan, S.; Li, Z.; Liu, J. Potassium Fertilization Stimulates Sucrose-to-Starch Conversion and Root Formation in Sweet Potato (Ipomoea batatas (L.) Lam.). Int. J. Mol. Sci. 2021, 22, 4826. https://doi.org/10.3390/ijms22094826
Gao Y, Tang Z, Xia H, Sheng M, Liu M, Pan S, Li Z, Liu J. Potassium Fertilization Stimulates Sucrose-to-Starch Conversion and Root Formation in Sweet Potato (Ipomoea batatas (L.) Lam.). International Journal of Molecular Sciences. 2021; 22(9):4826. https://doi.org/10.3390/ijms22094826
Chicago/Turabian StyleGao, Yang, Zhonghou Tang, Houqiang Xia, Minfei Sheng, Ming Liu, Shenyuan Pan, Zongyun Li, and Jingran Liu. 2021. "Potassium Fertilization Stimulates Sucrose-to-Starch Conversion and Root Formation in Sweet Potato (Ipomoea batatas (L.) Lam.)" International Journal of Molecular Sciences 22, no. 9: 4826. https://doi.org/10.3390/ijms22094826