Gibberellic Acid與Abscisic Acid對矮生稻幼苗生長的影響

Effect of Gibberellic Acid and Abscisic on the Elongation Growth of Dwarf Rice Seeding

胡淼琳 ； 楊冠政

《師大生物學報》 11卷 (1976/10) Pp. 9-26

https://doi.org/10.29812/BBNTNU.197610.0002

摘要

GA3明顯地促進矮生稻（Oryzae Sative C. V. I-Geo Gon）幼苗的生長，ABA則強烈抑制之。當ABA與GA3同時存在時，兩者之間顯現出相互作用的現象。RNA總量的測定和32P嵌入（incorporation）的實驗都顯示出GA3促進RNA的合成在生長受促進之前發生，而DNA的增加則在RNA之後。ABA抑制幼苗的生長，降低核酸與蛋白的含量。當ABA與GA3同時存在時，其結果顯示：1.當ABA濃度達到5 x 10^(-5) M以上時，加入GA3無相互作用的現象。2.ABA濃度低於5 x 10^(-5) M時，GA3與ABA之間有拮抗作用（Antagonism）發生。以5 x 10^(-6) M ABA和5 x 10^(-4) M GA3共同處理幼苗至第五天，幼苗的高度已經恢復到蒸餾水培養的水準，RNA的含量有明顯的回昇，但仍有部份的抑制，DNA蛋白質和幼苗乾重量雖有參差不等的增加，却仍有50%以上的抑制。由此可見ABA與GA3之間的相互作用為部份（partial）和非競爭性（non-competitive）者，亦即這兩種荷爾蒙之間的作用可能只有部份的相連，這一相關部份顯示出拮抗的現象。非相關部份的ABA的抑制作用則非加入GA3所能解除。另外，本實驗亦就GA3與ABA在種子發芽時，α-澱粉酶的合成和根生長間之相互作用情形一併加以討論。

並列摘要

GA3 enhances the elongation growth of early dwarf rice (Oryzae sntiva cv, I-Geo-Gen) seedlings. Markedly preceding growth of the shoots is an increased RNA synthesis, as shown by total RNA determination and 32P-incorporation into RNA. But the increase in DNA content is later and is evident after treatment with GA3 for 4 days. ABA inhibits shoot elongations, nucleic acid and protein synthesis. When GA3 is added together with ABA, it is found: 1) the inhibition of shoot growth by higher concentration of ABA (above 5 x 10^(-5) M) can't be overcome by the additton of GA3 even at reasonably high concentration. 2) the inhibition of growth by ABA below the concentration of 5 x 10^(-5) M can be gradually overcome by increasing the cone, of GA3. When ABA (5 x 10^(-6)M) is added together with 5 x 10^(-4) M GA3 for 5 days, shoot length of the dwarf rice seedlings reaches the level of dist, water control. RNA content is largely reversed, but the content of DNA, protein and shoot dry weight, though increased slightly, are still markedly inhibited over 50%. These results suggest that the interaction between GA3 and ABA is partial, incomplete and non-competitive, i. e., GA3 can only overcome part of the inhibitory action of ABA, while the other part, maybe the most part, on which they both act differently and independently can't be overcome by the addition of axogenous GA3. In addition, the interaction between these 2 hormones in the control of seed germination, α-amylase synthesis in embryoless half endosperms, and root growth o f seedlings are studied and discussed.