Arigita Luis, Tamés Ricardo Sánchez, González Aida
Laboratory Fisiología Vegetal, Dpto. de Biología de Organismos y Sistemas, Facultad de Biología, Universidad de Oviedo, C/ Catedrático Rodrigo Uría s/n, 33071 Oviedo, Spain.
Funct Plant Biol. 2004 Jul;31(6):603-609. doi: 10.1071/FP03184.
The relationship between polyamines and ethylene is controversial because the degree of interference of one pathway with the other may differ according to species, stage of development and experimental procedure. In this paper, we modify ethylene biosynthesis by the addition of aminoethoxyvinylglicine (AVG) or 1-aminocyclopropane-1-carboxylic acid (ACC) and study how it affects polyamine content and development of kiwifruit explants (Actinidia deliciosa CS Liang. & AR Fergusson). Cultured under ventilation where ethylene did not accumulate in the culture vessels, kiwi explants had higher ACC synthase activity and lower polyamine content than those grown without ventilation. In explants cultured in the reference medium, putrescine was the more abundant polyamine and spermine was only detected in the free fraction irrespective of ventilation. Under ventilation, addition of ACC to the culture medium inhibited organogenesis, there was less spermidine and spermine was not detected. Addition of AVG to the culture medium increased both the number of shoots and the amount of polyamines, and inhibited ACC synthase, so S-adenosylmethionine (SAM) led to increasing synthesis of spermidine and spermine. The increase in putrescine is more difficult to explain on the basis of inhibition of ethylene biosynthesis. The increase in the number of shoots in kiwi explants due to AVG addition may be attributed to the lack of ethylene in the atmosphere of the vessels or the increase in free polyamines.
多胺与乙烯之间的关系存在争议，因为一条途径对另一条途径的干扰程度可能因物种、发育阶段和实验程序而异。在本文中，我们通过添加氨基乙氧基乙烯基甘氨酸（AVG）或1-氨基环丙烷-1-羧酸（ACC）来改变乙烯的生物合成，并研究其如何影响猕猴桃外植体（美味猕猴桃梁CS & 弗格森AR）的多胺含量和发育。在通风条件下培养，乙烯不会在培养容器中积累，猕猴桃外植体的ACC合酶活性较高，多胺含量低于未通风培养的外植体。在参考培养基中培养的外植体中，无论是否通风，腐胺都是含量更丰富的多胺，而精胺仅在游离部分中检测到。在通风条件下，向培养基中添加ACC会抑制器官发生，亚精胺含量减少且未检测到精胺。向培养基中添加AVG会增加芽的数量和多胺的含量，并抑制ACC合酶，因此S-腺苷甲硫氨酸（SAM）导致亚精胺和精胺的合成增加。基于对乙烯生物合成的抑制，腐胺的增加更难以解释。添加AVG导致猕猴桃外植体芽数量增加可能归因于培养容器环境中乙烯的缺乏或游离多胺的增加。
