Hidayah Anik, Nisak Rizka Rohmatin, Susanto Febri Adi, Nuringtyas Tri Rini, Yamaguchi Nobutoshi, Purwestri Yekti Asih
Biotechnology Study Program, The Graduate School, Universitas Gadjah Mada, Jl. Teknika Utara, Sleman, Yogyakarta, 55281, Indonesia.
Agricultural Environmental Division, Indonesian Agency For Agricultural Research and Development, Jl. Raya Jakenan-Jaken Km. 5, Central Java, 59182, Pati, Indonesia.
Bot Stud. 2022 Jul 25;63(1):24. doi: 10.1186/s40529-022-00354-9.
Saline land in coastal areas has great potential for crop cultivation. Improving salt tolerance in rice is a key to expanding the available area for its growth and thus improving global food security. Seed priming with salt (halopriming) can enhance plant growth and decrease saline intolerance under salt stress conditions during the subsequent seedling stage. However, there is little known about rice defense mechanisms against salinity at seedling stages after seed halopriming treatment. This study focused on the effect of seed halopriming treatment on salinity tolerance in a susceptible cultivar, IR 64, a resistant cultivar, Pokkali, and two pigmented rice cultivars, Merah Kalimantan Selatan (Merah Kalsel) and Cempo Ireng Pendek (CI Pendek). We grew these cultivars in hydroponic culture, with and without halopriming at the seed stage, under either non-salt or salt stress conditions during the seedling stage.
The SES scoring assessment showed that the level of salinity tolerance in susceptible cultivar, IR 64, and moderate cultivar, Merah Kalsel, improved after seed halopriming treatment. Furthermore, seed halopriming improved the growth performance of IR 64 and Merah Kalsel rice seedlings. Quantitative PCR revealed that seed halopriming induced expression of the OsNHX1 and OsHKT1 genes in susceptible rice cultivar, IR 64 and Merah Kalsel thereby increasing the level of resistance to salinity. The expression levels of OsSOS1 and OsHKT1 genes in resistant cultivar, Pokkali, also increased but there was no affect on the level of salinity tolerance. On the contrary, seed halopriming decreased the expression level of OsSOS1 genes in pigmented rice cultivar, CI Pendek, but did not affect the level of salinity tolerance. The transporter gene expression induction significantly improved salinity tolerance in salinity-susceptible rice, IR 64, and moderately tolerant rice cultivar, Merah Kalsel. Induction of expression of the OsNHX1 and OsHKT1 genes in susceptible rice, IR 64, after halopriming seed treatment balances the osmotic pressure and prevents the accumulation of toxic concentrations of Na, resulting in tolerance to salinity stress.
These results suggest that seed halopriming can improve salinity tolerance of salinity-susceptible and moderately tolerant rice cultivars.
沿海地区的盐碱地具有巨大的作物种植潜力。提高水稻的耐盐性是扩大其生长可用面积从而改善全球粮食安全的关键。用盐进行种子引发（盐引发）可以促进植物生长，并降低后续幼苗期在盐胁迫条件下的盐不耐受性。然而，关于种子盐引发处理后水稻幼苗期对盐度的防御机制知之甚少。本研究聚焦于种子盐引发处理对一个感盐品种IR 64、一个耐盐品种Pokkali以及两个有色水稻品种南加里曼丹红稻（Merah Kalsel）和短黑粳稻（CI Pendek）耐盐性的影响。我们在水培条件下种植这些品种，种子阶段进行或不进行盐引发处理，幼苗期处于非盐胁迫或盐胁迫条件下。
盐害评分评估表明，感盐品种IR 64和中度耐盐品种Merah Kalsel在种子盐引发处理后的耐盐水平有所提高。此外，种子盐引发改善了IR 64和Merah Kalsel水稻幼苗的生长性能。定量PCR显示，种子盐引发诱导了感盐水稻品种IR 64和Merah Kalsel中OsNHX1和OsHKT1基因的表达，从而提高了对盐度的抗性水平。耐盐品种Pokkali中OsSOS1和OsHKT1基因的表达水平也有所增加，但对耐盐水平没有影响。相反，种子盐引发降低了有色水稻品种CI Pendek中OsSOS1基因的表达水平，但对耐盐水平没有影响。转运蛋白基因表达的诱导显著提高了感盐水稻IR 64和中度耐盐水稻品种Merah Kalsel的耐盐性。盐引发种子处理后，感盐水稻IR 64中OsNHX1和OsHKT1基因表达的诱导平衡了渗透压，防止了有毒浓度的Na积累，从而产生对盐胁迫的耐受性。
这些结果表明，种子盐引发可以提高感盐和中度耐盐水稻品种的耐盐性。
