Xu Y Y, Wang M G, Jia J F
Institute of Botany, Chinese Academy of Sciences, Beijing 100093.
Shi Yan Sheng Wu Xue Bao. 2001 Mar;34(1):11-5.
Seeds of sainfoin (Onobrychis vicaefolia Scop.) were carried in the recoverable satellite 940703 and recovered from earth orbit from China in 1994. The progeny seeds were obtained by producing in field. The salt tolerant calluses were selected by screening seedling and callus on 1.5% NaCl-containing medium, reviving growth on NaCl- free medium and selecting callus on 1.2% NaCl-containing medium. The salt tolerant line callus maintained the normal ability to regenerate plant. The salt tolerant line callus exhibited cross-resistance to PEG stress. The variant appeared higher efficiency than control to accumulate proline under salt stress, however, under nonstress condition it had lower proline level than control, which suggested that the higher efficiency to synthesize proline under stress condition may be more important than higher level in tissue under nonstress condition. The mechanism of proline synthesis in the selected callus was considered to result from the alteration in gene sensitivity to water regulation at transcription level. Acrylamide gradient electrophoresis showed that new isoenzyme form with MW 175 kD and 75 kD of superoxide dismutase and esterase respectively appeared in salt torlerant callus. It was indicated that the combination of space mutagenesis with tissue culture could be used for the selection of salt tolerant sainfoin line in vitro.
红豆草（Onobrychis vicaefolia Scop.）种子搭载于940703返回式卫星，于1994年从中国地球轨道回收。通过田间种植获得子代种子。通过在含1.5% NaCl的培养基上筛选幼苗和愈伤组织，在无NaCl培养基上恢复生长并在含1.2% NaCl的培养基上选择愈伤组织，筛选出耐盐愈伤组织。耐盐系愈伤组织保持了正常的植株再生能力。耐盐系愈伤组织对PEG胁迫表现出交叉抗性。变异体在盐胁迫下积累脯氨酸的效率高于对照，然而，在非胁迫条件下其脯氨酸水平低于对照，这表明在胁迫条件下较高的脯氨酸合成效率可能比在非胁迫条件下组织中较高的脯氨酸水平更重要。所选愈伤组织中脯氨酸合成的机制被认为是由于转录水平上基因对水分调节的敏感性改变所致。丙烯酰胺梯度电泳表明，耐盐愈伤组织中分别出现了分子量为175 kD的超氧化物歧化酶和75 kD的酯酶的新同工酶形式。结果表明，空间诱变与组织培养相结合可用于体外筛选耐盐红豆草品系。
