采后脱落酸处理促进甘薯块根愈伤木栓组织的形成

本研究以’北京1号’甘薯为试验材料,人工模拟机械损伤后采用不同浓度(25、50、100、200 mg/L)脱落酸(ABA)进行愈伤处理,研究采后ABA处理对甘薯块根的愈伤作用。结果表明:采后ABA处理能有效促进甘薯伤口处愈伤木栓组织的形成,其中以100 mg/LABA愈伤3 d效果最佳。采后ABA处理能有效提高甘薯愈伤组织苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)和多酚氧化酶(PPO)活性,提升总酚、类黄酮含量,减少甘薯重量损失。相关性分析表明,ABA处理甘薯木质素含量与总酚、类黄酮含量之间呈极显著相关(P<0.01),PAL酶活力与POD和PPO酶活力呈极显著相关(P<0.01)。综上所述,采后ABA处理可通过激发甘薯损伤部位组织的苯丙烷代谢、提高愈伤防御酶活性及次生代谢产物的合成,达到促进甘薯块根愈伤形成的目的。

Formation of Callus Suberin Tissue of Postharvest Sweet Potato Roots with Abscisic Acid

In this study, ‘Beijing No.1’ sweet potato was used as the experimental material. After artificially simulating mechanical damage, the sweet potato was treated with different concentrations (25, 50, 100, 200 mg/L) of abscisic acid (ABA). The purpose of this research was to study the callus effect of ABA treatment on postharvest sweet potato roots. ABA treatment could effectively promote the formation of callus in sweet potato wounds, and the best effect was obtained with 100 mg/L ABA for 3 days. ABA treatment could effectively increase the activity of phenylalanine ammonialyase (PAL), peroxidase (POD) and polyphenol oxidase (PPO) in sweet potato callus, increase total phenol and flavonoid content, and reduce sweet potato weight loss. Correlation analysis showed that there was a significant correlation between the content of lignin, total phenol as well as flavonoids of ABA treated sweet potato (P<0.01). The activity of PAL enzyme was significantly correlated with the activity of POD and PPO after ABA treatment (P<0.01). In summary, postharvest ABA treatment can achieve the purpose of promoting the callus formation of sweet potato roots by inducing phenylpropanoid metabolism, improving callus defense enzyme activity and synthesis of secondary metabolites in damaged parts.