Mechanisms and effective control of physiological browning phenomena in plant cell cultures
Mechanisms and effective control of physiological browning phenomena in plant cell cultures
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植物细胞培养中生理褐变现象的机制和有效控制
DOI：
10.1111/ppl.12382
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发表时间：
2016-01-01
影响因子：
6.4
通讯作者：
Yu, Long-jiang
中科院分区：
文献类型：
--
作者：
Dong, Yan-shan;Fu, Chun-hua;Yu, Long-jiang
褐变现象普遍存在于植物细胞培养物中，严重阻碍了植物细胞培养物的科学研究和广泛应用。到目前为止，由于植物细胞培养中的褐变机理尚不清楚，这一问题仍未得到很好的控制。本文以红豆杉细胞和甘草细胞为材料，研究了红豆杉细胞和甘草细胞严重褐变的机理。我们的结果表明，褐变是一种生理酶反应，糖调节的酚类生物合成在褐变中起着决定性的作用。此外，为了确定参与酶促褐变反应的特定化合物，对黄连细胞的转录谱和代谢产物进行了分析，并对从褐变培养基中提取的褐变化合物进行了紫外扫描和高效液-质联用分析，发现苯丙烷途径衍生的黄酮类化合物是主要化合物，杨梅素和槲皮素是褐变反应的主要底物。抑制类黄酮的生物合成可以防止褐变的发生，而赤霉酸(GA(3))通过抑制类黄酮的合成有效地控制了褐变的发生，进一步证实了类黄酮是褐变的主要原因。在此基础上，提出了植物细胞培养过程中酶促褐变机理的模型，并提出了有效的控制途径。
Browning phenomena are ubiquitous in plant cell cultures that severely hamper scientific research and widespread application of plant cell cultures. Up to now, this problem still has not been well controlled due to the unclear browning mechanisms in plant cell cultures. In this paper, the mechanisms were investigated using two typical materials with severe browning phenomena, Taxus chinensis and Glycyrrhiza inflata cells. Our results illustrated that the browning is attributed to a physiological enzymatic reaction, and phenolic biosynthesis regulated by sugar plays a decisive role in the browning. Furthermore, to confirm the specific compounds which participate in the enzymatic browning reaction, transcriptional profile and metabolites of T. chinensis cells, and UV scanning and high-performance liquid chromatography-mass spectrometry (HPLC-MS) profile of the browning compounds extracted from the brown-turned medium were analyzed, flavonoids derived from phenylpropanoid pathway were found to be the main compounds, and myricetin and quercetin were deduced to be the main substrates of the browning reaction. Inhibition of flavonoid biosynthesis can prevent the browning occurrence, and the browning is effectively controlled via blocking flavonoid biosynthesis by gibberellic acid (GA(3)) as an inhibitor, which further confirms that flavonoids mainly contribute to the browning. On the basis above, a model elucidating enzymatic browning mechanisms in plant cell cultures was put forward, and effective control approaches were presented.