ABSTRACT

Relatively little is known about the physiological significance of betalain pigments. To investigate a possible protective role for betalains (betacyanin), from UV-B irradiation, two cultivars of A. tricolor, Red-Leaf (RL) and Green-Leaf (GL) were obtained and VIGS method was used to produce isogenic derivatives of RL. Short-term responses to UV-B in the leaves were compared with and without detectable betalains. Following exposure, the red and green tissues showed similar decrease in photosynthetic capacity and in the increased production of UV-B stress markers including melatonin, flavonoids, phenolics, and PAL1 and RCD1 gene transcripts. Red tissues showed an increase in photosynthetic pigments under UV-B treatment, whereas the photosynthetic pigments and CAB1 and CAB2 gene transcripts decreased. The responses observed were similar for both high-betacyanin (RL) plants, and green plants (VIGS, GL), from which it was concluded that betacyanin does not have a UV-B protective role in amaranth leaves, under the experimental conditions.

摘要

关于甜菜碱色素的生理意义的了解相对较少。为了研究甜菜碱（甜菜碱）的可能保护作用，通过UV-B辐照，获得了两个颜色的A. tricolor品种：红叶（RL）和绿叶（GL），并使用VIGS方法生产了RL。比较有无可检测的甜菜碱对叶片中UV-B的短期反应。暴露后，红色和绿色组织显示出类似的光合作用能力下降，并增加了包括褪黑素，类黄酮，酚类以及PAL1和RCD1基因转录物在内的UV-B胁迫标记的产量。红色组织在UV-B处理下显示出光合色素的增加，而光合作用色素和CAB1和CAB2基因转录物减少。在高β-花青素（RL）植物和绿色植物（VIGS，GL）上观察到的响应相似，从中可以得出结论，在实验条件下，β-花青素在a菜叶中没有UV-B保护作用。