Jesmin Akter, Anh La Hoang, Mai Nguyen Phuong, Khanh Tran Dang, Xuan Tran Dang
Graduate School of Advanced Science and Engineering, Hiroshima University, 1-5-1 Kagamiyama, Higashi-Hiroshima 739-8529, Japan.
Department of Agricultural Extension, Ministry of Agriculture, Dhaka 1215, Bangladesh.
Plants (Basel). 2023 Jun 18;12(12):2359. doi: 10.3390/plants12122359.
Salinity is a severe stress that causes serious losses in rice production worldwide. This study, for the first time, investigated the effects of fulvic acid (FA) with various concentrations of 0.125, 0.25, 0.5, and 1.0 mL/L on the ability of three rice varieties, Koshihikari, Nipponbare, and Akitakomachi, to cope with a 10 dS/m salinity level. The results show that the T3 treatment (0.25 mL/L FA) is the most effective in stimulating the salinity tolerance of all three varieties by enhancing their growth performance. T3 also promotes phenolic accumulation in all three varieties. In particular, salicylic acid, a well-known salt-stress-resistant substance, is found to increase during salinity stress in Nipponbare and Akitakomachi treated with T3 by 88% and 60%, respectively, compared to crops receiving salinity treatment alone. Noticeably, the levels of momilactones A (MA) and B (MB) fall in salt-affected rice. However, their levels markedly rise in rice treated with T3 (by 50.49% and 32.20%, respectively, in Nipponbare, and by 67.76% and 47.27%, respectively, in Akitakomachi), compared to crops receiving salinity treatment alone. This implies that momilactone levels are proportional to rice tolerance against salinity. Our findings suggest that FA (0.25 mL/L) can effectively improve the salinity tolerance of rice seedlings even in the presence of a strong salt stress of 10 dS/m. Further studies on FA application in salt-affected rice fields should be conducted to confirm its practical implications.
盐度是一种严重的胁迫因素，导致全球水稻产量严重损失。本研究首次调查了浓度分别为0.125、0.25、0.5和1.0 mL/L的黄腐酸（FA）对三个水稻品种越光、日本晴和秋田小町应对10 dS/m盐度水平能力的影响。结果表明，T3处理（0.25 mL/L FA）通过提高三个品种的生长性能，在刺激其耐盐性方面最为有效。T3还促进了这三个品种中酚类物质的积累。特别是，一种著名的抗盐胁迫物质水杨酸，在T3处理的日本晴和秋田小町中，与仅接受盐度处理的作物相比，在盐胁迫期间分别增加了88%和60%。值得注意的是，在受盐影响的水稻中，稻瘟菌素A（MA）和B（MB）的水平下降。然而，与仅接受盐度处理的作物相比，在T3处理的水稻中，它们的水平显著上升（在日本晴中分别上升50.49%和32.20%，在秋田小町中分别上升67.76%和47.27%）。这意味着稻瘟菌素水平与水稻对盐度的耐受性成正比。我们的研究结果表明，即使在10 dS/m的强盐胁迫下，FA（0.25 mL/L）也能有效提高水稻幼苗的耐盐性。应进一步开展关于FA在盐渍稻田中应用的研究，以确认其实际意义。
