AUTHOR=Huang Xuan , Yao Jingwen , Zhao Yangyang , Xie Dengfeng , Jiang Xue , Xu Ziqin 

TITLE=Efficient Rutin and Quercetin Biosynthesis through Flavonoids-Related Gene Expression in Fagopyrum tataricum Gaertn. Hairy Root Cultures with UV-B Irradiation

JOURNAL=Frontiers in Plant Science

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/plant-science/articles/10.3389/fpls.2016.00063

DOI=10.3389/fpls.2016.00063

ISSN=1664-462X

ABSTRACT=<p>Transformed hairy roots had been efficiently induced from the seedlings of <italic>Fagopyrum tataricum</italic> Gaertn. due to the infection of <italic>Agrobacterium rhizogenes</italic>. Hairy roots were able to display active elongation with high root branching in 1/2 MS medium without growth regulators. The stable introduction of <italic>rol</italic>B and <italic>aux</italic>1 genes of <italic>A. rhizogenes</italic> WT strain 15834 into <italic>F. tataricum</italic> plants was confirmed by PCR analysis. Besides, the absence of <italic>vir</italic>D gene confirmed hairy root was bacteria-free. After six different media and different sources of concentration were tested, the culturing of TB7 hairy root line in 1/2 MS liquid medium supplemented with 30 g l<sup>-1</sup> sucrose for 20 days resulted in a maximal biomass accumulation (13.5 g l<sup>-1</sup> fresh weight, 1.78 g l<sup>-1</sup> dry weight) and rutin content (0.85 mg g<sup>-1</sup>). The suspension culture of hairy roots led to a 45-fold biomass increase and a 4.11-fold rutin content increase in comparison with the suspension culture of non-transformed roots. The transformation frequency was enhanced through preculturing for 2 days followed by infection for 20 min. The UV-B stress treatment of hairy roots resulted in a striking increase of rutin and quercetin production. Furthermore, the hairy root lines of TB3, TB7, and TB28 were chosen to study the specific effects of UV-B on flavonoid accumulation and flavonoid biosynthetic gene expression by qRT-PCR. This study has demonstrated that the UV-B radiation was an effective elicitor that dramatically changed in the transcript abundance of <italic>ftpAL</italic>, <italic>FtCHI</italic>, <italic>FtCHS</italic>, <italic>FtF3H</italic>, and <italic>FtFLS-1</italic> in <italic>F. tataricum</italic> hairy roots.</p>