| This article has been：Browse 349Times Download 40Times |
scan it! |
|
|
| DOI：10.13522/j.cnki.ggps.2025382 |
|
| Improving water use efficiency and salt-drought tolerance in rice seedlings via gibberellic acid seed soaking and light supplementation |
|
LIN Shimiao, ZHU Mei, LIU Shuoshuo, SUN Danchen
|
|
School of Engineering, Anhui Agricultural University, Hefei 230036, China
|
| Abstract: |
| 【Objective】Rice seedlings are susceptible to salt and drought stresses. Herein, we investigate the efficacy of seed soaking with gibberellic acid combined with red-blue light supplementation on water use efficiency and stress resistance of rice seedlings under salt and drought stress.【Method】Rice variety ‘Jingzhan No. 1’ was used in the experiment. The agronomic treatments included seed soaking in distilled water without supplemental lighting (WN) and seed soaking in a solution with 150 mg/L gibberellic acid combined with nighttime far-red-blue light supplementation (GL). There were two drought treatments with PEG-6000 concentrations in the medium set at 10% (T1) and 15% (T2) respectively, two salinity treatments with NaCl concentrations of 0.075 mol/L (T3) and 0.15 mol/L (T4) respectively, and four combined salt-drought treatments formed by combining T1–T2 with T3–T4. During the experiment, we measured dry matter accumulation, root-to-shoot ratio, photosynthetic traits, water use efficiency, and antioxidant and oxidative stress indicators.【Result】The GL treatment alleviated the inhibitory effects of salt and drought, both individually and in combination, on seedling growth. When other conditions were the same, GL increased aboveground and belowground dry weights by 3.22%-12.90% and 17.19%-40.63%, respectively, and root-to-shoot ratio by 14.56%-54.08% compared with the WN treatment. GL also improved net photosynthetic rate and leaf water use efficiency by 0.81%-41.81% and 2.19%-71.47%, respectively. GL enhanced the activities of antioxidant enzymes (superoxide dismutase and peroxidase), while reducing catalase activity, malondialdehyde content, and hydrogen peroxide levels. Correlation analysis showed that water use efficiency was most strongly correlated with photosynthetic rate (R2=0.53) and least correlated with peroxidase activity (R2=0.071). The factors affecting water use efficiency were ranked as follows: photosynthetic rate＞malondialdehyde ≈ catalase＞superoxide dismutase＞hydrogen peroxide＞root-to-shoot ratio＞peroxidase.【Conclusion】Seed soaking in gibberellic acid solution combined with far-red-blue light supplementation improves water use efficiency and enhances salt-drought tolerance of rice seedlings primarily due to the improved carbon assimilation rather than solely because of the enhanced antioxidant enzyme activity. |
| Key words: rice; combined salt-drought stress; gibberellic acid seed soaking; far-red-blue light supplementation; water use efficiency |
|
|
