離層酸(ABA)與高粱幼苗耐冷性之關係
Other Title
The Relationship Between ABA and Chilling Tolerance in Sorghum (Sorghum bicolor L.) Seedlings
Journal
雜糧作物生產技術改進研討會專刊
Part Of
農業試驗所特刊第49號
Pages
203-227
Date Issued
1995-05
Date
1995-05
Author(s)
Abstract
本試驗以不同低溫耐性的高粱品系為材料，探討低溫與ABA處理對其生理反應之影響。試驗結果顯示，2R品系在低溫下氣孔快速關閉，葉片鮮重與水分含量均可維持，植株並無明顯枯萎的現象；而不耐低溫的80A品系，低溫處理後氣孔無法快速關閉，鮮重下降，葉片明顯脫水枯萎。此外低溫下2R品系根部活力較80A為高，由木質部泌出液的結果也可看出低溫下2R品系根部水分傳導能力（root hydraulic conductance）較80A為高，故仍可在低溫下維持根部吸水能力。二品系低溫處理後，ABA均有累積的現象，地上部在低溫處理24小時後開始累積，根部在6小時有一累積高峰，而後則下降，然而2R與80A二品系間，在ABA含量上並無差異。若將不耐低溫的高粱幼苗（80A）以10-4 MABA前處理24小時後再進入低溫處理，可顯著減少80A幼苗低溫受害情形。80A幼苗經ABA前處理24小時後，氣孔導度與蒸散速率已明顯下降，因此再移入低溫處理時由於氣孔已經關閉，故低溫下的蒸散作用顯著減少，植株鮮重與水分含量均可維持，葉片亦無枯萎脫水現象。此外，ABA也可明顯增加根部活力與吸水能力，顯示ABA可促使80A植株在低溫下維持水分平衡，而減少低溫傷害。
The objectives of this research were to study the physiological responses of sorghum seedlings to low temperature. The role of ABA on chilling tolerance was also investagated. Results showed that under chilling condition, water content and fresh weight of shoots of 80A decreased rapidly and the leaves dehydrated significantly after being exposed for 1 day. However, under the same condition little water lose in 2R leaves was observed. Electrical leakage in leaves of 80A increased rapidly with the time of cold treatment, whereas apparent less increasing were shown in 2R seedlings. The differences of leaf stomatal conductance and root hydraulic conductance between 2R and 80A were also examined. Leaf stomtal conductance of 2R reduced rapidly after transferring to 5/5℃ treatment, whereas 80A stayed at a high level similar with the control during the chilling period. In addition, 2R showed a significantly higher root TTC reductase activity and xylem exudation rate than did 80A under low temperature. When seedlings were subjected to 5℃, the level of endogenous abscisic acid in both shoot and root increased rapidly. However, no discernible difference in the level of chilling- induced abscisic acid was observed between 2R and 80A. Results also showed that pretreatment of ABA in solution could significantly prevent 80A seedling from chilling injury significantly. Two hours after 10-4 M ABA pretreatment, transpiration rate and stomatal conductance of the 3rd leaf of sorghum seedling were dramatically reduced. The lower level of leaf transpiration rate could prevent water loss and maintain fresh weight of 80A seedling during low temperature treatment. Exogenous application of ABA also increased root TTC reductase activity and the amount of xylem sap remarkably. The present results suggested that ABA may be involved in the amelioration process of sorghum seedlings to chilling injury through keeping water balance under cold condition.
Event(s)
雜糧作物生產技術改進研討會
Subjects
高粱
耐冷性
離層酸
木質部泌出液
葉片蒸散速率
根部活力
Sorghum
Chilling tolerance
ABA
Leaf transpiration rate
Xylem sap
Root TTC activity
Publisher
農業試驗所
Type
conference paper
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