ABSTRACT ICE1 (Inducer of CBF Expression 1), a MYC-type bHLH transcription factor, is a regulator of cold tolerance in Arabidopsis. Indica rice, which occupies the major rice cultivated area, is highly sensitive to cold stress. Hence in this study, Arabidopsis ICE1 (AtICE1) was overexpressed in indica rice to analyze its role in reproductive stage cold and other abiotic stress tolerance to indica rice. AtICE1 was overexpressed by using stress inducible AtRD29A promoter in mega rice cv. MTU1010. Under cold stress conditions, AtICE1 overexpression lines showed lower accumulation of MDA and H2O2, higher membrane stability, and thus higher seedling survival rate than the WT plants. Expression levels of OsDREB1A, OsMYB3R2, and OsTPP1 were significantly higher in transgenics as compared with WT under cold stress conditions. AtICE1 transgenic rice plants produced 44–60% higher grain yield as compared with WT plants under control conditions in three independent experiments. Of the three AtICE1 overexpression lines, two lines produced significantly higher grain yield as compared with WT plants after recovery from cold, salt and drought stresses. AtICE1 overexpression lines showed significantly higher stomatal density and conductance under non-stress conditions. qRT-PCR analysis showed that expression levels of stomatal pathway genes viz., OsSPCH1, OsSPCH2, OsSCR1, OsSCRM1, OsSCRM2 and OsMUTE were significantly higher in AtICE1 transgenics as compared with WT plants. The components of water use viz., stomatal conductance, photosynthesis, and instantaneous WUE were higher in transgenics as compared with WT plants. The results showed that AtICE1 confers multiple stress tolerance to indica rice, and the role of ICE1 in stress tolerance and stomatal development is conserved across species.

中文翻译：

---

拟南芥ICE1过表达提高籼稻产量和多种非生物胁迫耐受性

摘要 ICE1（CBF 表达诱导剂 1）是一种 MYC 型 bHLH 转录因子，是拟南芥耐寒性的调节剂。占主要水稻种植面积的籼稻对冷胁迫高度敏感。因此，在本研究中，拟南芥ICE1（AtICE1）在籼稻中过表达，以分析其在籼稻生殖期寒冷和其他非生物胁迫耐受性中的作用。AtICE1 通过在巨型水稻品种中使用胁迫诱导型 AtRD29A 启动子过表达。MTU1010。在冷胁迫条件下，AtICE1 过表达株系表现出较低的 MDA 和 H2O2 积累，较高的膜稳定性，因此比 WT 植物具有更高的幼苗存活率。与冷胁迫条件下的WT相比，OsDREB1A、OsMYB3R2和OsTPP1的表达水平在转基因中显着更高。在三个独立实验中，与对照条件下的 WT 植物相比，AtICE1 转基因水稻植物的谷物产量高出 44-60%。在三个 AtICE1 过表达品系中，在从冷、盐和干旱胁迫中恢复后，与 WT 植物相比，两个品系产生了显着更高的谷物产量。AtICE1 过表达系在非胁迫条件下显示出显着更高的气孔密度和电导。qRT-PCR 分析表明，与 WT 植物相比，AtICE1 转基因植物中气孔途径基因 OsSPCH1、OsSPCH2、OsSCR1、OsSCRM1、OsSCRM2 和 OsMUTE 的表达水平显着更高。与 WT 植物相比，转基因植物的水分利用成分，即气孔导度、光合作用和瞬时 WUE 更高。