Agriculture Reference
In-Depth Information
(a) Nuclease protection assays
(b) Sonication protection assays
He et al. (
2003
) used positively charged amino-modified bioconjugated silica
nanoparticles for conjugation with DNA and protection of DNA from cleavage. Cui
et al. (
2012
) have reported the use of PEI-modified magnetic nanoparticles for the
binding with plasmid DNA. Moreover, the nanoparticle/DNA conjugate can protect
the DNA against degradation by exonuclease or endonuclease by preventing the
access to the cleavage sites. This can be demonstrated by agarose gel electropho-
resis. The efficiency of gene delivery can be affected by the amount and charge to
mass ratio of nanoparticle/DNA conjugate.
10.3 Biotransformation in Plant by Using Nanoparticles
Transport of nanoparticles in plants is being unraveled, and various studies are now
ascertaining the role of different metal nanoparticles on plant growth and
metabolism.
10.3.1 Mode of Entry, Transport, and Effects of Different
Nanoparticles in Plants
The plant cell wall acts as a barrier, preventing the easy entry of any external agent
including metal NPs into plant cells. The cell wall pore diameter ranging from 5 to
20 nm (Fleischer et al.
1999
; Navarro et al.
2008
) allows easy passage of the NPs
having the diameter less than the pore diameter of the cell wall and enters the
plasma membrane of the cell (Moore
2006
; Navarro et al.
2008
). There is also a
possibility of pore size enlargement or an induction of new pores in the cell wall
upon interaction with engineered NPs which in turn enhance their uptake. Internal-
ization of NPs also occurs by endocytosis process, wherein a cavity-like structure is
formed around the nanoparticles by a phospholipid bilayer. NPs may also cross the
membrane using membrane-embedded transporter proteins or through ion chan-
nels. On entering the cytoplasm, NPs may interact with different cytoplasmic
organelles and biomolecules, affecting the metabolic processes in the cytoplasm
(Jia et al.
2005
). When NPs are applied on the leaf surface, they can enter through
stomatal openings or through the bases of trichomes (Eichert et al.
2008
; Fernandez
and Eichert
2009
; Uzu et al.
2010
). The NPs accumulated on photosynthetic surface
can cause foliar heating resulting into the alterations to gas exchange. The stomatal
obstruction caused by the NPs produces changes in various physiological and
cellular functions of plants (Da Silva et al.
2006
). Studies on the uptake and
formation of nanoparticles within plants have also generated interest among the
investigators on the use of plants as source for NP synthesis (Fig.
10.4
).
