水分胁迫下冰草体内脱落酸与游离脯氨酸的积累关系

在水分胁迫下,脱落酸(ABA)和脯氨酸(Pro)在冰草叶中都会大量积累。不同冰草种所积累的ABA和Pro在量上没有相关性。外源ABA也能诱导Pro在冰草叶中积累。但ABA诱导的Pro积累可以被细胞分裂索(BA)所抑制,而水分胁迫诱导的Pro积累只能部分地被BA抑制。这两种抑制的机理是一致的,即BA对水分胁迫诱导Pro积累的部分抑制作用是由于抑制了水分胁迫下所积累的ABA的作用。这些结果表明:水分胁迫下,植物体内ABA与Pro的积累并没有直接因果关系,即积累的ABA不是引起Pro积累的直接触发引子,但增加的ABA对Pro积累有一定的促进作用。

The Relationship Between the Accumulations of Abscisic Acid and Free Proline in Wheatgrass under Water Stress

Under water stress condition,proline accumulation in Bameng leaves was faster and more than that in Ephraim leaves; at 24h after water stress, proline contents increased from 0.072 and 0.064 to 0.804 and 0.322 mg/gFw respectively. However, ABA accumulation in Bameng leaves was smaller than that in Ephraim; at 24h after water stress, ABA level increased from 0.46 and 0.24 to 0.86 and 4.14μg/gFw respectively. Exogenous ABA also induced proline accumulation in Ephraim leaves. Proline and ABA contents in Ephraim leaves did not obviously change when the root system of plants was pretreated with 7×10~(-5)mol/L BA for 42h. BA pretreatment did not influence wilt-induced ABA accumulation, but partly inhibited wilt-induced proline accumulation and completely inhibited ABA-induced proline accumulation. It is suggested that there are no correlation between ABA and proline accumulations, added ABA is not the direct cause for proline accumulation during water stress, but it may be stimulate proline accumulation to some extent.