2024-03-28T15:31:37Zhttps://eprints.lib.hokudai.ac.jp/dspace-oai/requestoai:eprints.lib.hokudai.ac.jp:2115/734212022-11-17T02:08:08Zhdl_2115_20049hdl_2115_141Control of elicitor-induced oxidative burst by abscisic acid associated with growth of Saccharina japonica (Phaeophyta, Laminariales) sporophytesShimizu, KazukiUji, ToshikiYasui, HajimeMizuta, HiroyukiAbscisic acidElicitorGrowthlodoperoxidaseKelpOxidative burst660In this study, the oligoguluronate elicitor-induced oxidative burst (OB) was monitored continuously in young and mature Saccharina japonica sporophytes based on luminol chemiluminescence using a photon counter. The iodoperoxidase (IPO) activity, abscisic acid (ABA), and polyphenol contents were also compared in the different growth stages. The elicitor-induced OB occurred within 1 min and reached its maximum in 15-20 min after treatment in all growth stages. The active elicitor-induced OB was stronger in the young sporophytes than the older sporophytes. The IPO activity in the different growth stages also exhibited a similar pattern to the elicitor-induced OB. These results suggest that the elicitor-induced OB and the subsequent high haloperoxidase activity comprise a major defence mechanism in young sporophytes. By contrast, ABA accumulated with the growth of the sporophytes. Interestingly, ABA treatment suppressed the elicitor-induced OB during growth and enhanced the elicitor-independent IPO activity even in the young sporophytes. In addition, the polyphenol content was higher in the older sporophytes than the younger sporophytes. These observations show that dramatic changes occur in the characteristic defences against biotic stresses as the sporophyte grows, as well as suggesting that ABA is closely linked with these changes. Moreover, the IPO activity recovered slightly in the sorus, which is the reproductive tissue, thereby suggesting that a higher ABA content increases the defence activity and the success of reproduction.SpringerJournal Articleapplication/pdfhttp://hdl.handle.net/2115/73421https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/73421/1/J.%20Appl.%20Phycol._30%282%29_1371-1379.pdf0921-8971Journal of Applied Phycology302137113792018-04enginfo:doi/10.1007/s10811-017-1320-2This is a post-peer-review, pre-copyedit version of an article published in Journal of Applied Phycology. The final authenticated version is available online at: http://dx.doi.org/10.1007/s10811-017-1320-2author