College of Coastal Agricultural Sciences, Guangdong Ocean University, Zhanjiang, Guangdong, China.
National Saline-tolerant Rice Technology Innovation Center, South China, Zhanjiang, Guangdong, China.
PeerJ. 2024 Mar 14;12:e17068. doi: 10.7717/peerj.17068. eCollection 2024.
The aim of this experiment was to investigate the effects of exogenous sprays of 5-aminolevulinic acid (5-ALA) and 2-Diethylaminoethyl hexanoate (DTA-6) on the growth and salt tolerance of rice ( L.) seedlings. This study was conducted in a solar greenhouse at Guangdong Ocean University, where 'Huanghuazhan' was selected as the test material, and 40 mg/L 5-ALA and 30 mg/L DTA-6 were applied as foliar sprays at the three-leaf-one-heart stage of rice, followed by treatment with 0.3% NaCl (W/W) 24 h later. A total of six treatments were set up as follows: (1) CK: control, (2) A: 40 mg⋅ L 5-ALA, (3) D: 30 mg⋅ L DTA-6, (4) S: 0.3% NaCl, (5) AS: 40 mg⋅ L 5-ALA + 0.3% NaCl, and (6) DS: 30 mg⋅ L DTA-6+0.3% NaCl. Samples were taken at 1, 4, 7, 10, and 13 d after NaCl treatment to determine the morphology and physiological and biochemical indices of rice roots. The results showed that NaCl stress significantly inhibited rice growth; disrupted the antioxidant system; increased the rates of malondialdehyde, hydrogen peroxide, and superoxide anion production; and affected the content of related hormones. Malondialdehyde content, hydrogen peroxide content, and superoxide anion production rate significantly increased from 12.57% to 21.82%, 18.12% to 63.10%, and 7.17% to 56.20%, respectively, in the S treatment group compared to the CK group. Under salt stress, foliar sprays of both 5-ALA and DTA-6 increased antioxidant enzyme activities and osmoregulatory substance content; expanded non-enzymatic antioxidant AsA and GSH content; reduced reactive oxygen species (ROS) accumulation; lowered malondialdehyde content; increased endogenous hormones GA3, JA, IAA, SA, and ZR content; and lowered ABA content in the rice root system. The MDA, HO, and O contents were reduced from 35.64% to 56.92%, 22.30% to 53.47%, and 7.06% to 20.01%, respectively, in the AS treatment group compared with the S treatment group. In the DS treatment group, the MDA, HO, and O contents were reduced from 24.60% to 51.09%, 12.14% to 59.05%, and 12.70% to 45.20%. In summary, NaCl stress exerted an inhibitory effect on the rice root system, both foliar sprays of 5-ALA and DTA-6 alleviated damage from NaCl stress on the rice root system, and the effect of 5-ALA was better than that of DTA-6.
本实验旨在研究外源喷 5-氨基乙酰丙酸（5-ALA）和 2-二乙氨基乙基己酸酯（DTA-6）对水稻（ L.）幼苗生长和耐盐性的影响。本研究在广东海洋大学太阳能温室中进行，选用‘黄花占’为试验材料，在水稻三叶一心期喷施 40mg/L 5-ALA 和 30mg/L DTA-6，24 小时后用 0.3%（W/W）NaCl 处理。共设置 6 种处理：（1）CK：对照，（2）A：40mg/L 5-ALA，（3）D：30mg/L DTA-6，（4）S：0.3%NaCl，（5）AS：40mg/L 5-ALA+0.3%NaCl，（6）DS：30mg/L DTA-6+0.3%NaCl。在 NaCl 处理后 1、4、7、10 和 13d 取样，测定水稻根系的形态和生理生化指标。结果表明，NaCl 胁迫显著抑制水稻生长，破坏抗氧化系统，增加丙二醛、过氧化氢和超氧阴离子的产生速率，影响相关激素含量。与 CK 组相比，S 组丙二醛含量、过氧化氢含量和超氧阴离子产生率分别从 12.57%增加到 21.82%、18.12%增加到 63.10%和 7.17%增加到 56.20%。在盐胁迫下，5-ALA 和 DTA-6 的叶面喷施均提高了抗氧化酶活性和渗透调节物质含量，扩大了非酶抗氧化剂 AsA 和 GSH 的含量，降低了活性氧（ROS）的积累，降低了丙二醛含量，增加了内源激素 GA3、JA、IAA、SA 和 ZR 的含量，降低了水稻根系中 ABA 的含量。与 S 组相比，AS 组 MDA、HO 和 O 的含量分别从 35.64%降低到 56.92%、22.30%降低到 53.47%和 7.06%降低到 20.01%。DS 组 MDA、HO 和 O 的含量分别从 24.60%降低到 51.09%、12.14%降低到 59.05%和 12.70%降低到 45.20%。综上所述，NaCl 胁迫对水稻根系有抑制作用，5-ALA 和 DTA-6 叶面喷施均可缓解 NaCl 胁迫对水稻根系的伤害，5-ALA 的效果优于 DTA-6。
