Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto, Japan.
PLoS One. 2011;6(9):e25257. doi: 10.1371/journal.pone.0025257. Epub 2011 Sep 26.
The yeast Candida boidinii capable of growth on methanol proliferates and survives on the leaves of Arabidopsis thaliana. The local methanol concentration at the phyllosphere of growing A. thaliana exhibited daily periodicity, and yeast cells responded by altering both the expression of methanol-inducible genes and peroxisome proliferation. Even under these dynamically changing environmental conditions, yeast cells proliferated 3 to 4 times in 11 days. Among the C1-metabolic enzymes, enzymes in the methanol assimilation pathway, but not formaldehyde dissimilation or anti-oxidizing enzymes, were necessary for yeast proliferation at the phyllosphere. Furthermore, both peroxisome assembly and pexophagy, a selective autophagy pathway that degrades peroxisomes, were necessary for phyllospheric proliferation. Thus, the present study sheds light on the life cycle and physiology of yeast in the natural environment at both the molecular and cellular levels.
能够以甲醇为生长基质的酵母毕赤氏酵母（Candida boidinii）在拟南芥（Arabidopsis thaliana）的叶片上增殖和存活。生长中的拟南芥叶际的局部甲醇浓度表现出昼夜周期性，酵母细胞通过改变甲醇诱导基因和过氧化物酶体增殖的表达来做出响应。即使在这些动态变化的环境条件下，酵母细胞在 11 天内增殖了 3 到 4 倍。在 C1 代谢酶中，甲醇同化途径中的酶，但不是甲醛异化或抗氧化酶，对于在叶际增殖是必需的。此外，过氧化物酶体的组装和过氧化物酶体的选择性自噬途径（pexophagy）降解过氧化物酶体，对于叶际增殖都是必需的。因此，本研究从分子和细胞水平揭示了酵母在自然环境中的生命周期和生理学。
