盐预处理对大麦种子萌发和小孢子愈伤形成的影响

Effects of salt pretreatment on seed germination and microspore callus formation in barley

为探究盐预处理对大麦种子萌发和小孢子培养的影响,以大麦耐盐品种花11和盐敏感品种花30为材料,比较了它们在不同盐浓度预处理下,种子萌发过程中的发芽率、主根长以及小孢子培养过程中的愈伤组织产量差异,同时对2个品种在小孢子时期响应盐胁迫的4个关键基因的表达进行了研究。结果显示:花30的种子和小孢子在无NaCl和低浓度NaCl预处理时,对盐胁迫的耐受性均低于花11,但经高浓度NaCl(萌发期为15 g/L,小孢子时期为300 mg/L)预处理后,花30的种子和小孢子对高浓度盐胁迫的耐受性均显著增强,且发芽率、主根长和愈伤产量均显著高于花11;通过对2个品种在盐预处理下的发芽率、主根长以及愈伤产量相对值的相关性分析发现,2个品种在种子萌发期和小孢子时期响应盐预处理的相对值呈显著正相关。同时,在小孢子培养阶段,经过300 mg/L NaCl预处理后,花30中小热激蛋白基因HvsHSP1和翻译起始因子1基因HveIF1A的表达量在高浓度盐胁迫下较花11显著上调。因此,供试品种间在种子萌发过程和小孢子培养过程对盐预处理的响应差异在某种程度上可能具有一致性,HvsHSP1和HveIF1A基因可能与盐敏感品种在小孢子时期响应NaCl盐诱导存在关系。

The salt tolerant cultivar H11 and salt sensitive cultivar H30 were used to study the effects of salt pretreatment on seed germination and microspore callus formation in barley.The germination rate,taproot length during the seed germination and the yield of callus in the microspore culture stage was compared under the salt pretreatments.The expression of four key genes at the microspore stage of the two cultivars was investigated under salt stress.The results showed that the seeds and microspores of H30 were less tolerant to salt than that of H11 under 0 g/L NaCl and low NaCl pretreatment.Under the high concentration of NaCl pretreatment(15 g/L NaCl in germination stage and 300 mg/L in microspore stage),the salt tolerance of H30 was significantly enhanced.The germination rate,taproot length and the yield of callus were significantly superior to that of H11 under high concentration of salt stress.The results of the correlation analysis of germination rate,taproot length and callus yield between the two cultivars showed that the relative values of the differences between the two cultivars at the stage of germination and microspore were significantly positively correlated.The gene HvsHSP1 and HveIF1A of H30 were significantly up-regulated at the stage of microspore culture in comparison with that of H11 after 300 mg/L NaCl pretreatment.It is indicated that the differences in the response of tested barley cultivars to salt pretreatment at the stage of seed germination and microspore may be consistent.HvsHSP1 and HveIF1A of salt sensitive cultivar may be related with the response of NaCl induction at the stage of microspore.