菌根蝴蝶蘭提昇抗蕙蘭嵌紋病毒與適應高光逆境
能力之研究

蝴蝶蘭為台灣花卉產業中重要的盆花植物，栽培過程常面臨病毒病害蔓延與高光等生物與非生物逆境，本研究藉由菌根真菌與蘭花之間共生關係的建立，期能提供可以解決上述問題之雙贏策略。本研究第一部分，發展以真菌自發性螢光為基礎的顯微技術，在藍光的激發下，不經染劑染色的根部切片，其菌絲及菌絲團呈現黃綠色螢光，而細胞質則顯現紅色螢光，因而菌根構造可以明顯的被鑑別出來。此新技術為有效且具專一性之方法，可以篩選菌根蝴蝶蘭植株供後續病毒抗病性及高光馴化研究之利用。本研究第二部分，評估及分析三種植物生長促進真菌(R02、R04及R19)對兩品種蝴蝶蘭(Phalaenopsis ‘V3’與Phalaenopsis ‘V265’)植體內蕙蘭嵌紋病毒(CymMV)系統性運移與病程相關蛋白基因(PR1)之影響。菌根植株葉片在接種CymMV兩週後，具有較對照組植株低之感染率；且該病毒從接種葉片至上位葉片的系統性運移速度也較緩慢，因而受害程度降低。再者，菌根植株葉片的系統性獲得抗病性(SAR)指標基因PR1，也明顯地在48小時內被顯著誘導表達。因此，本研究推測菌根蝴蝶蘭可以透過PR1的表達啟動，有效地誘導對CymMV的系統性抗病性，惟保護效果會因蘭菌菌株與蘭花品系組合而有不同。本研究第三部分，測定栽培於高光環境下兩品種菌根蝴蝶蘭(Phalaenopsis ‘KC1410’與Phalaenopsis ‘KC32’)之生長品質與光合作用效能，藉以評估它們的光馴化策略。R02菌根的接種可以刺激高光栽培蝴蝶蘭，較R04菌根及非菌根對照組(NM)具有較高的營養生長、夜間二氧化碳的吸收速率、光合作用表現(ФPSII與ETR)及光利用效率(qP與NPQ)等。高光下具有較高之光合作用表現與較低之非光化學消散能力，即為菌根植株在高光下生存的典型反應。特別的是，菌根感染的表現會依蘭花品種與其健康情形(無病毒或病毒感染)而有所不同。因此，蘭花菌根可以單獨或同時刺激蘭花之生長，和/或緩和CymMV病害之發展，應具有發展成為天然、生態友善及有效的生物防治劑之潛力。

關鍵字

自發螢光；菌根感染；蕙蘭嵌紋病毒；誘導性系統抗病性；光合作用表現能力；光輻射利用效能；光馴化

並列摘要

Phalaenopsis orchids are important potted flowering plants in floriculture of Taiwan that encounter biotic and abiotic stress during cultivation e.g. virus spreading and highlight (HL) stress. The establishment of symbiotic relationships between mycorrhizal fungi and orchids may provide win-win strategies to solve these problems. A fungal autofluorescence-based microscopy was developed to evaluate the establishment of symbiotic relationship of Phalaenopsis spp. in response to mycorrhizal colonization. With blue-light excitation, fungal hyphae and peletons embedded in root sections without toxic dyes emitted yellow-green light from the cytoplasm which emitted red light. Therefore, the mycorrhizal structures are apparently been discriminated. This new technique provides an efficient and specific observation method to screen mycorrhizal Phalaenopsis for subsequent studies of viral resistance and highlight acclimation. Effects of three plant-growth-promoting-fungi (PGPF) (R02, R04 and R19) on systemic movement of Cymbidium Mosaic Virus (CymMV) on Phalaenopsis ‘V3’ & ‘V265’ were determined, and the expression of PR1 (pathogenesis-related protein 1) involving in systemic viral resistance was analyzed. Leaves of mycorrhizal plants after 2 months CymMV challenge have lower infection rate than the control plants, and the systemic viral movement from inoculation leaf to upper leaf was moderated. Otherwise, the systemic acquired resistance (SAR) indicator gene PR1 has obviously been highly induced within 48 hrs in mycorrhizal plant leaves. Therefore, mycorrhizal Phalaenopsis can effectively induce systemic resistance to CymMV via the induction of PR1, whereas protection efficacy varied depending on the combination of orchid mycorrhizal fungi (OMF) isolates and orchid cultivars. Growth quality and photosynthetic performance of two mycorrhizal Phalaenopsis (Phalaenopsis ‘KC1410’ & ‘KC32’) cultivating under highlight environment was determined to evaluate their photoacclimation strategies. OMF R02 inoculation stimulated the highlight-grown Phalaenopsis’s growth, and increased their CO2 uptake rate, photosynthetic performance (ФPSII (PSII operating efficiency) and ETR (electron transport rate), and radiation-use efficiency (qP (photochemical quenching) and NPQ (non-photochemical quenching) than the R04 and non-mycorrhizal (NM) control plants. Higher photosynthetic performance and lower NPQ are typical response of mycorrhizal plants to survive the HL stress. Notably, the performance of mycorrhizal colonization was varied according to the orchid species and its health (virus free or infected). It is concluded that orchid mycorrhiza can either stimulate orchid growth or moderate CymMV-disease development, or simultaneously achieve both. Therefore, it is potential of being developed into a natural, eco-friendly, and efficient biological control agents.

並列關鍵字

autofluorescence ； mycorrhizal colonization ； Cymbidium mosaic virus ； induced systemic resistance ； photosynthetic performance ； radiation use efficiency ； photoacclimation

參考文獻

Anderson, A.B. 1991. Symbiotic and asymbiotic germination and growth of Spiranthes magnicamporum (Orchidaceae). Lindleyana 6:183–186.

Baker, N.R. 2008. Chlorophyll fluorescence: a probe of photosynthesis in vivo. Ann. Rev. Plant Biol. 59:89–113.

Cameron, D.D., I. Johnson, J.R. Leake, and D.J. Read. 2007. Mycorrhizal acquisition of inorganic phosphorus by the green-leaved terrestrial orchid Goodyera repens. Ann. Bot. 99:831–834.

Horton, P., and A. Ruban. 2004. Molecular design of the photosystem II light- harvesting antenna: photosynthesis and photoprotection. J. Exp. Bot. 56:365– 373.

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菌根蝴蝶蘭提昇抗蕙蘭嵌紋病毒與適應高光逆境能力之研究

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