Cadmium uptake via apoplastic bypass flow in Oryza sativa

Journal of Plant Research - It is known that rice roots take up cadmium (Cd) via the symplastic route mediated by membrane-bound mineral transporters. Here we provide evidence that apoplastic...     

Triggering antiviral response by RIG-I-related RNA helicases

TLRs detect several classes of virus-associated molecules, such as ssRNA, CpG-DNA and dsRNA, and transduce signals leading to the production of IFN. Recently discovered cytoplasmic RNA helicases, RIG-I and MDA5, selectively sense viral RNA species. Gene disruption studies revealed the critical but non-redundant function of RIG-I and MDA5 in host antiviral responses.     

A most distant intergeneric hybrid offspring (Larcon) of lesser apes, <Emphasis Type="Italic">Nomascus leucogenys</Emphasis> and <Emphasis Type="Italic">Hylobates lar</Emphasis>

Unlike humans, which are the sole remaining representatives of a once larger group of bipedal apes (hominins), the “lesser apes” (hylobatids) are a diverse radiation with numerous extant species. Consequently, the lesser apes can provide a valuable evolutionary window onto the possible interactions (e.g., interbreeding) of hominin lineages coexisting in the same time and place. In the present work, we employ chromosomal analyses to verify the hybrid ancestry of an individual (Larcon) produced by two of the most distant genera of lesser apes, Hylobates (lar-group gibbons) and Nomascus (concolor-group gibbons). In addition to a mixed pelage pattern, the hybrid animal carries a 48-chromosome karyotype that consists of the haploid complements of each parental species: Hylobates lar (n = 22) and Nomascus leucogenys leucogenys (n = 26). Studies of this animal’s karyotype shed light onto the processes of speciation and genus-level divergence in the lesser apes and, by extension, across the Hominoidea.     

The effects of spacer sequences on silencing efficiency of plant RNAi vectors

RNA interference (RNAi) has been used to suppress gene expression in various eukaryotic organisms. In plants, RNAi can be induced by introduction of an RNAi vector that transcribes a self-complementary hairpin RNA. Most basic RNAi constructs have an inverted repeat interrupted with a spacer sequence. To test silencing capability of RNAi constructs, we developed an in vivo assay that is based on the RNAi-mediated changes of the α-linolenic acid content in hairy roots. A tobacco endoplasmic reticulum ω-3 fatty acid desaturase (NtFAD3) is the main enzyme for production of α-linolenic acid of root membrane lipids. Tobacco hairy roots transformed with the RNAi vectors against the NtFAD3 gene showed a decrease in α-linolenic acid content. The frequency of RNA silencing was more affected by spacer sequence than by spacer length, at least between 100 and 1800 bp. Since significant amounts of hairpin RNA against the NtFAD3 gene remained in the transgenic plants displaying a weak silencing phenotype, low degree of silencing was attributed to low efficiency of hairpin RNA processing mediated by Dicer-like proteins. Our results show the possibility of producing a broad range of the RNAi-induced silencing phenotypes by replacing the spacer sequence of RNAi construct.     

Abscinazole-E1, a novel chemical tool for exploring the role of ABA 8'-hydroxylase CYP707A

We developed abscinazole-E1 (Abz-E1), a specific inhibitor of abscisic acid (ABA) 8′-hydroxylase (CYP707A). This inhibitor was designed and synthesized as an enlarged analogue of uniconazole (UNI), a well-known plant growth retardant, which inhibits a gibberellin biosynthetic enzyme (ent-kaurene oxidase, CYP701A) as well as CYP707A. Our results showed that Abz-E1 functions as a potent inhibitor of CYP707A and a poor inhibitor of CYP701A both in vitro and in vivo. Abz-E1 application to plants resulted in improved desiccation tolerance and an increase in endogenous ABA.     

A trial of production of the plant-derived high-value protein in a plant factory: Photosynthetic photon fluxes affect the accumulation of recombinant miraculin in transgenic tomato fruits

One of the ultimate goals of plant science is to test a hypothesis obtained by basic science and to apply it to agriculture and industry. A plant factory is one of the ideal systems for this trial. Environmental factors affect both plant yield and the accumulation of recombinant proteins for industrial applications within transgenic plants. However, there have been few reports studying plant productivity for recombinant protein in closed cultivation systems called plant factories.To investigate the effects of photosynthetic photon flux (PPF) on tomato fruit yield and the accumulation of recombinant miraculin, a taste-modifying glycoprotein, in transgenic tomato fruits, plants were cultivated at various PPFs from 100 to 400 (µmol m⁻² s⁻¹) in a plant factory. Miraculin production per unit of energy used was highest at PPF100, although miraculin production per unit area was highest at PPF300. The commercial productivity of recombinant miraculin in transgenic tomato fruits largely depended on light conditions in the plant factory. Our trial will be useful to consider the trade-offs between the profits from production of high-value materials in plants and the costs of electricity.Key words: light, molecular farming, recombinant miraculin, taste-modifying protein, transgenic tomato