研究背景：內生細菌的定義為在表面滅菌植物內檢測到的細菌或從植物內部提取的細菌，不會對植物造成明顯的疾病或對植物是無害的。神經肽Y (NPY) 是一種從中樞神經元和外周神經元所分泌出來的抑制性神經傳遞物質。先前的研究結果已經證明NPY表現量可以在幾種抑鬱動物模式中被改變，並且可以藉由急性和重複地施加壓力進行差異性的調節。 實驗目的：這項研究的目的是檢驗我們的假設，即通過內生細菌的定殖可以產生高價值的水稻。 實驗方法：解澱粉芽孢桿菌(Bacillus amyloliquefaciens, BA)是作為內生細菌。ICR小鼠血漿中的NPY濃度是利用酶聯免疫吸附測定(ELISA)來檢測。此外，我們使用孔板測試模型來評估小鼠的與焦慮相關的行為。 實驗結果：水稻在經過BA菌定殖10天之後，其γ-氨基丁酸(GABA)的含量有明顯的增加。飼餵高GABA水稻的小鼠血漿中NPY含量(9.57±0.52 ng / ml)顯著高於飼餵對照水稻的小鼠(6.82±0.28 ng / ml)。此外，與餵食對照水稻的小鼠相比，在餵食高GABA水稻的小鼠中觀察到較少的焦慮相關行為。 結論：解澱粉芽孢桿菌(Bacillus amyloliquefaciens, BA)作為內生細菌能夠發生作用產生高GABA水稻，GABA可以上調血漿內的NPY水平以減少小鼠的焦慮。 關鍵字：解澱粉芽孢桿菌、內生細菌、γ-氨基丁酸、微生物組體、神經肽Y ;Abstract Background: Endophytic bacteria are defined as bacteria detected inside surface-sterilized plants or extracted from inside plants without causing apparent disease or no harmful effects on the plants. Neuropeptide Y (NPY) is a suppressive neurotransmitter that can be secreted from both the central and peripheral neurons. It has been previously demonstrated that the level of NPY can be altered in several animal models of depression, as well as be differentially regulated by acute and repeated stress.
Aim: The goal of this study is to test our hypothesis that high-value rice can be generated by colonization of endophytic bacteria.
Methods: Bacillus amyloliquefaciens (BA) was used as an endophytic bacterium. NPY concentrations in plasma of ICR mice were measured by the enzyme-linked immunosorbent assay (ELISA). Furthermore, a model of a hole-board test was used to evaluate the anxiety-related behavior in mice.
Results: Rice colonized with BA bacteria for ten days increased the content of in gamma-aminobutyric acid (GABA). The amount (9.57 ± 0.52 ng/ml) of NPY in the plasma of mice fed with high-GABA rice was significantly higher than that (6.82 ± 0.28 ng/ml) in mice fed with control rice. Moreover, less anxiety-related behavior was observed in mice fed with high-GABA rice in comparison with mice fed with control rice. Conclusion: Bacillus amyloliquefaciens (BA) functions as an endophytic bacterium to yield a high GABA rice that can upregulate the plasma level of NPY for reduction of the anxiety in mice.
Keywords: neuropeptide Y (NPY), gamma-aminobutyric acid (GABA), anxiety, Bacillus amyloliquefaciens, GABA(b) receptor antagonist, ultrasonic conditioning vocalization, hole-board test