影響根圈細菌產生吲哚乙酸之因子

Factors Affecting IAA Production by Rhizobacteria

陳睦鈞(M. C. Chen) ； 林宗俊(T. C. Lin) ； 黃振文(J. W. Huang)

《植物病理學會刊》 19卷3期 (2010/09) Pp. 201-212

https://doi.org/10.6649/PPB.201009_19(3).0004

摘要

本研究主要探討Paenibacillus polymyxa Gh1、Geobacillus thermoblucosidasius Gh4、Bacillusmegaterium Bg12及Microbacterium resistense Bg31等根圈細菌菌株產生吲哚乙酸(IAA)之影響因子。光照處理對4菌株產生IAA之濃度皆比無光照之處理低，其中尤以培養96小時最為明顯。4菌株在培養48小時後，它們的IAA產量均快速的提升。隨著培養溫度之上升，各菌株產生IAA的濃度亦呈現上升之趨勢，其中Bg31、Gh1、Gh4和Bg12菌株產生IAA的最適溫度分別為28℃、32℃、32℃與36℃。在酸鹼值測試研究中，於pH 7.5時，各菌株的IAA產量均表現最佳。氮素源中，色胺酸 (L-tryptophan)為各菌株產生IAA之決定性因子，隨著色胺酸濃度的提高，IAA產量亦隨之增加。碳素源對於各菌株產生IAA量的多寡會隨著不同碳素源及菌株的種類而有顯著的變異。測試不同的培養基質對菌量增殖及產生IAA之影響，發現大豆酪蛋白液態培養基(Trypic soy broth，TSB)優於其他培養基的處理。將番茄、甜瓜及蘿蔔種子分別浸泡於上述各菌株之細菌懸浮液，並種植於栽培基質中，結果發現Gh1、Gh4及Bg31等三菌株均可顯著促進甜瓜及番茄幼苗之生長。此外，將4菌株之TSB培養液混拌於介質，進而種植不同作物，結果顯示菌株Bg31促進蘿蔔生長之效果最佳。將蘿蔔幼苗培養在MS (Murashige andSkoog medium)植物組織培養液中，分別加入Bg31菌株之TSB培養液與IAA標準品，評估其對幼苗根系發展之影響，結果發現兩處理皆可促進側根之發育且使側根較為粗壯。

關鍵字

根圈細菌 ； 吲哚乙酸 ； 大豆酪蛋白液態培養基 ； 蘿蔔 ； 花生粕

並列摘要

The factors affecting indole acetic acid (IAA) production by four rhizobacterial isolates, i.e. Paenibacillus polymyxa Gh1, Geobacillus thermoblucosidasius Gh4, Bacillus megaterium Bg12 and Microbacterium resistense Bg31, were studied. The amount of IAA produced by the bacteria grown under illumination conditions was reduced signifinatly at 96 hpi (hours post incubation) in comparison with dark treatment. Under dark conditions, the yield of IAA was rapidly increased at for 48 hpi. The optimal temperature for IAA production was 28℃ for strain Bg31, 32℃ for strains Gh1 and Gh4, and 36℃for strain Bg12, and the 4 tested strains produced the highest amount of IAA at pH of 7.5. The Lform tryptophan was the key nitrogen source for the tested strains to produce IAA, and the quantity of IAA was increased by increasing the concentration of tryptophan in the culture medium. The effect of carbon sources on IAA production varied amoung different bacterial strains. Among the selected commercial media, tryptic soy broth (TSB) showed to contain the optimal combination of ingredients for the 4 bacterial stains to produce IAA and to increase their biomass. Seeds of tomato, melon and radish soaked in bacterial cell suspension and sown in peat moss were evaluated for their growth. The results indicated that Bg31, Gh1 and Gh4 could promote the growth of melon and tomato seedlings. When bacterial biomass was mixed with peat moss prior seed sowing, only TSB-cultivated Bg31 promoted the growth of radish seedlings. In vitro experiments showed that TSB-cultivated Bg31 promoted the development of lateral roots of radish seedlings, which was similar to the effect of IAA on root development.

並列關鍵字

rhizosphere bacteria ； indole-3-acetic acid ； tryptic soy broth ； radish ； peanut seed pomace