豌豆中脱落酸含量、叶片导性与土壤含水量之间的关系

Abscisic Acid Content and Leaf Conductance in Relation to Soil Water Content in Pisum sativum L.

脱落酸与植物水分胁迫的关系已进行了大量的研究,现已明确脱落酸可以抑制气孔的开放(Jones和 Mansfield 1970,Weyers和 Hillman 1979,Henson等 1989),但它的作用机制仍然很不清楚。已有报告指出,当土壤水分亏缺时,ABA可以作为根与地上部间的通讯信号,由很运到地上部并抑制气孔的开放(Blackman和 Davies1985,Gollan等 1986,Zhang和

In order to test whether stomataare responsive to soil water stress andwhether the response is mediated byABA, pea (Pisum Sativum L.) plantsare grown in soil with different watercontents for 20 days. ABA contentwas determined by enzyme-linked im-munosorbent assay (ELISA). Leafconductance was measured with theporometer (Heinz Waltz, Germany). The content of endogenous ABAin leaf increased as soil water contentdecreased (Fig. 1). Similar changeappeared in epidermis but at a lowerlevel. Roots accumulated ABA whenpea plants were under drought stress.The foremost 1 cm of root is more sen-sitive to water content of soil than theparts behind it (Fig. 2). Leaf conduc-tance decreased as soil water contentdropped below 70% (Fig. 3). Leafconductance was found to be negative-ly correlated with the ABA contents inleaf, leaf epidermis and in root, thecorrelation coefficients being statistical-ly significant (Fig. 4 and Fig. 5).