Effects of environmental conditions before gene transfer on the amount of influenza hemagglutinin transiently expressed in <I>Nicotiana benthamiana</I> leaves

Abstract

We investigated the effects of photosynthetic photon flux density PPFD , air temperature, and CO 2 concentration before gene transfer on the accumulation level of hemagglutinin HA , an influenza vaccine antigen, in Nicotiana benthamiana leaves in a transient gene expression system. Plants were treated for two weeks before gene transfer with different levels of PPFD, air temperature or CO 2 concentration in separate experiments. Leaf fresh mass FM , leaf HA content per unit FM, and leaf HA content per plant at 6 d post infiltration 6 DPI for gene transfer all tended to increase with increasing average PPFD during the treatment period. Leaf FM and leaf HA content per plant at 6 DPI were significantly greater at an average day air temperature of 25 C-30 C during the treatment period than at 20 C-25 C. No clear effects of CO 2 concentration were found on either growth or leaf HA content under the conditions tested in the present study. There was a positive correlation between leaf HA content per unit FM at 6 DPI and leaf FM at 0 or 6 DPI in plants grown under different PPFDs and air temperatures. Preparing plants with increased leaf FM by applying high PPFD and / or high air temperature before gene transfer should increase not only total HA yield per plant but also HA content per unit leaf biomass at harvest.

Non-destructive estimation of the amount of green fluorescent protein transiently expressing in <i>Nicotiana benthamiana</i> leaves with a viral vector

“…A frozen leaf sample was homogenized in a chilled buffer and centrifuged to obtain a crude extract, according to Matsuda et al (2012Matsuda et al ( , 2019. We used two independent methods to quantify GFP content in the same extract: a fluorescence method (FL) and ELISA.…”