Subscriber access provided by UNIVERSITY OF ADELAIDE LIBRARIES
Article
Assessment of effects of the long-term exposure of agricultural crops to carbon nanotubes Mohamed Hassen Lahiani, Zeid A Nima, Hector Villagarcia, Alexandru S. Biris, and Mariya Khodakovskaya J. Agric. Food Chem., Just Accepted Manuscript • DOI: 10.1021/acs.jafc.7b01863 • Publication Date (Web): 14 Aug 2017 Downloaded from http://pubs.acs.org on August 15, 2017
Just Accepted “Just Accepted” manuscripts have been peer-reviewed and accepted for publication. They are posted online prior to technical editing, formatting for publication and author proofing. The American Chemical Society provides “Just Accepted” as a free service to the research community to expedite the dissemination of scientific material as soon as possible after acceptance. “Just Accepted” manuscripts appear in full in PDF format accompanied by an HTML abstract. “Just Accepted” manuscripts have been fully peer reviewed, but should not be considered the official version of record. They are accessible to all readers and citable by the Digital Object Identifier (DOI®). “Just Accepted” is an optional service offered to authors. Therefore, the “Just Accepted” Web site may not include all articles that will be published in the journal. After a manuscript is technically edited and formatted, it will be removed from the “Just Accepted” Web site and published as an ASAP article. Note that technical editing may introduce minor changes to the manuscript text and/or graphics which could affect content, and all legal disclaimers and ethical guidelines that apply to the journal pertain. ACS cannot be held responsible for errors or consequences arising from the use of information contained in these “Just Accepted” manuscripts.
Journal of Agricultural and Food Chemistry is published by the American Chemical Society. 1155 Sixteenth Street N.W., Washington, DC 20036 Published by American Chemical Society. Copyright © American Chemical Society. However, no copyright claim is made to original U.S. Government works, or works produced by employees of any Commonwealth realm Crown government in the course of their duties.
Page 1 of 37
Journal of Agricultural and Food Chemistry
1
2
Assessment of Effects of the Long-term Exposure of Agricultural
3
Crops to Carbon Nanotubes
4 5
Mohamed H. Lahiani1, Zeid Nima2, Hector Villagarcia1, Alexandru S. Biris2, Mariya V.
6
Khodakovskaya1*
7 8 9 10
1
-Department of Biology, University of Arkansas at Little Rock, Little Rock, Arkansas, 72205.
2-
Center for Integrative Nanotechnology Science, University of Arkansas at Little Rock, Little
Rock , Arkansas, 72205. *Author for correspondence:
[email protected] 11
1 ACS Paragon Plus Environment
Journal of Agricultural and Food Chemistry
12 13
ABSTRACT
14 15
Carbon-based nanomaterials (CBNs) were described as nanomaterials possessing abilities of
16
plant growth regulators. Here, we investigated the effects of long-term exposure of multi-walled
17
carbon nanotubes (MWCNTs) on the growth of three important crops (barley, soybean, corn).
18
The cultivation of all tested species was carried in hydroponics supplemented with 50µg/ml of
19
MWCNTs. After 20 weeks of continuous exposure to the nanomaterials, no significant toxic
20
signs on plant development were observed. Several positive phenotypical changes were recorded
21
in addition to the enhancement of photosynthesis in MWCNTs-exposed crops. Raman
22
spectroscopy with point-by-point mapping proved that MWCNTs added to hydroponics solution
23
moved into all tested species and were distributed in analyzed organs (leaves, stems, roots,
24
seeds).
25
agriculture. However, documented presence of MWCNTs in different organs of all exposed
26
crops again highlighted the importance of detail risk assessment of nano-contaminated plants
27
moving into the food chain.
Our results confirmed the significant potentials of CBN’s applications in plant
28 29
KEYWORDS
30
CBNs uptake, carbon nanotubes, plant growth, detection of carbon nanotubes in plants,
31
hydroponics system
32
2 ACS Paragon Plus Environment
Page 2 of 37
Page 3 of 37
33
Journal of Agricultural and Food Chemistry
INTRODUCTION
34
A wide range of CBNs (carbon nanotubes, carbon nanohorns, graphene) may stimulate seed
35
germination, plant growth 1-4, production of flowers/fruits 5 and activate plant cell division 1, 6. It
36
was shown that CBNs are capable of penetrating plant cell walls as well as thick seed coat
37
Positive effects of CBNs in planta are reproducible for different crop species
38
achievable by a number of delivery methods including spray, introduction in soil/growth medium
39
7, 10
1, 3, 7, 10-13
3, 7-9
.
and
. Reproducibility and consistency of effects of CBNs are solid foundations for the
40
development of new plant growth regulators based in “nano-formula”. However, in order to
41
develop the technology that will be suitable for food crops and approved by Federal Agencies,
42
many questions have to be answered. Firstly, it has to be proven that long-term exposure of
43
plants to CBNs will not lead to toxic effects in planta. Previously, it had been demonstrated that
44
positive effects of CBNs can be observed when CBNs were used in relatively low doses (10-100
45
ug/ml) 7, 10, 14. However, long-term contact with plants with CBNs used as fertilizers may modify
46
the response of exposed plants. Secondly, a comprehensive risk assessment of food crops
47
exposed to CBNs to humans and animals should be performed at several levels including the
48
confirmation of contamination of exposed plants with nanomaterials, toxicity tests using in vitro
49
and in vivo experiments. The first group of risk assessment experiments (detection of
50
nanomaterials on exposed plants) will rely on the development of sensitive and relatively simple
51
analytical techniques. The detection of carbon nanomaterials in complex biological systems is
52
rather difficult, given their carbon chemical structure, which cannot be easily discriminated from
53
that of the actual biological system. The existing methods for detection and visualization of
54
CBNs in organic tissues have many challenges. Using microscopic methods such as confocal
55
laser scanning microscopy (CLSM)15, transmission electron microscopy (TEM) 16, and scanning 3 ACS Paragon Plus Environment
Journal of Agricultural and Food Chemistry
56
electron microscopy (SEM)17,
18
57
reason, these methods should be combined with other spectroscopic methods for confirmation of
58
the nanoparticle presence. Two of the most promising spectroscopic techniques for the
59
carbonaceous nanomaterials are Raman spectroscopy (based on light scattering) and
60
photoacoustic microscopy (PAM) (based on light absorption). Raman spectroscopy uses the
61
specific peaks characteristic to the CBNs and their intensity to detect and actually map the
62
presence of these nanomaterials in the biological systems1, 7, 13, 19, 20. Therefore, the combination
63
of CBNs exposure to plant systems and the Raman spectroscopy analysis of their presence and
64
possibly distribution could elucidate some of the underlying phenomena at the interface between
65
nanoscale materials and agriculturally valuable species.
, CNTs can be misled for plant cellular structures. For this
66
The goal of this investigation was to understand the biological response of three crop species
67
(barley, corn, and soybean) after long-term exposure to a representative type of CBNs (multi-
68
walled carbon nanotubes, MWCNTs). The long-term exposure to MWCNTs was achieved by
69
the cultivation of all tested species in hydroponics solution supplemented with MWCNTs for 20
70
weeks. The response of plants on such treatment was monitored by phenotypical studies,
71
characterization of the photosynthetic ability of exposed plants and proof of translocation of
72
MWCNTs in different organs (Figure 1).
73 74 75
MATERIALS AND METHODS Delivery of MWCNTs to plants though addition to hydroponic systems
76
The hydroponic system was obtained from Hydrofarm ® (Grand Prairie, TX). Each tray
77
contained six planters and plants were supported with clay pebbles. The system was linked with
78
an air pump to keep roots and nutrient solutions well aerated. A water pump was used to provide 4 ACS Paragon Plus Environment
Page 4 of 37
Page 5 of 37
Journal of Agricultural and Food Chemistry
79
a continuous flow of nutrients and carbon nanotubes in the solution. The trays were filled with
80
10 L of deionized water and supplemented with 0.5 ml of nutrient solution per 1 L of water. The
81
solution level was kept constant by checking the solution level daily, using a view/drain tube.
82
Nutrient solutions were provided weekly for the hydroponic systems. The hydroponic control
83
systems consisted of water and nutrients solution only. However, the treated hydroponic systems
84
included a solution of MWCNT. MWCNTs were synthesized at the Center of integrative for
85
Nanotechnology Sciences at the University of Arkansas at Little Rock. The Carbon
86
nanomaterials were characterized as described earlier by Lahiani et al., (2013). MWCNTs were
87
dispersed using a QSonica, LLC (Newtown, CT) sonicator. MWCNTs were added to the 2-week
88
old seedlings in hydroponics for three consecutive weeks as following: 100 mg in week 1 and an
89
addition of 200 mg in weeks 2 and 3. Using a water level indicator, the water level was
90
maintained at 10L during the whole experiment. The growth of control plants and plant exposed
91
to MWCNTs was monitored by: A) counting the number of leaves, internodes, fruits (soybean
92
and corn), spikelet (barley) ; B) measuring the shoot length, internode length , fruit length, lateral
93
branches (soybean and corn), tillers (barley); C) determining the total fresh/dry weight of shoots,
94
leaves, roots and fruits.
95 96
Statistics for tests of germination and plant growth All assays were performed in triplicate. All figures are represented as mean values ± SE
97
(standard errors). All data were analyzed using SPSS® software by performing repeated measure
98
ANOVA for time-effect analysis and ANOVA and posthoc analysis using the Tukey test for
99
treatment differences. Statistical significance was determined by p Vicia faba L.) seedlings under combined stress of lead and cadmium. J.
386
Hazard. Mater. 2014, 274, 404-412.
387
33.
388
(< i> Amaranthus tricolor L) and the role of ascorbic acid as an antioxidant. J. Hazard.
389
Mater. 2012, 243, 212-222.
390
34.
391
(Amaranthus tricolor L) and the role of ascorbic acid as an antioxidant. J. Hazard. Mater. 2012,
392
243, 212-222.
Khodakovskaya, M. V.; Lahiani, M. H., Role of Nanoparticles for Delivery of Genetic
Begum, P.; Ikhtiari, R.; Fugetsu, B., Potential Impact of Multi-Walled Carbon Nanotubes
Begum, P.; Ikhtiari, R.; Fugetsu, B., Graphene phytotoxicity in the seedling stage of
Jiang, Y.; Hua, Z.; Zhao, Y.; Liu, Q.; Wang, F.; Zhang, Q. In The Effect of Carbon
Wang, C.; Liu, H.; Chen, J.; Tian, Y.; Shi, J.; Li, D.; Guo, C.; Ma, Q., Carboxylated
Begum, P.; Fugetsu, B., Phytotoxicity of multi-walled carbon nanotubes on red spinach
Begum, P.; Fugetsu, B., Phytotoxicity of multi-walled carbon nanotubes on red spinach
18 ACS Paragon Plus Environment
Page 19 of 37
Journal of Agricultural and Food Chemistry
393
35.
Giraldo, J. P.; Landry, M. P.; Kwak, S. Y.; Jain, R. M.; Wong, M. H.; Iverson, N. M.;
394
Ben‐Naim, M.; Strano, M. S., A Ratiometric Sensor Using Single Chirality Near‐Infrared
395
Fluorescent Carbon Nanotubes: Application to In Vivo Monitoring. Small 2015, 11, 3973–3984.
396
36. Kole, C.; Kole, P.; Randunu, K. M.; Choudhary, P.; Podila, R.; Ke, P. C.; Rao, A. M.;
397
Marcus, R. K., Nanobiotechnology can boost crop production and quality: first evidence from
398
increased plant biomass, fruit yield and phytomedicine content in bitter melon (Momordica
399
charantia). BMC biotechnology 2013, 13, 1.
400
37.
401
M.; Mizukami, H.; Bianco, A.; Baba, Y., Trafficking and subcellular localization of multiwalled
402
carbon nanotubes in plant cells. ACS nano 2011, 5, 493-499.
403
38.
404
plant cell biology: carbon nanotubes as organelle targeting nanocarriers. RSC Advances 2013, 3,
405
4856-4862.
406
39.
407
Limbach, L. K., No Evidence for Cerium Dioxide Nanoparticle Translocation in Maize Plants.
408
Environ. Sci. Technol. 2010, 44, 8718-8723.
409
40.
410
the brain of juvenile large mouth bass. Environ. Health Perspect 2004, 112, 1058-1062.
411
41.
412
Nanobiotechno 2014, 12, 16.
413
42.
414
Ono, A.; Kamata, E.; Hirose, A., No toxicological effects on acute and repeated oral gavage
Serag, M. F.; Kaji, N.; Gaillard, C.; Okamoto, Y.; Terasaka, K.; Jabasini, M.; Tokeshi,
Serag, M. F.; Kaji, N.; Habuchi, S.; Bianco, A.; Baba, Y., Nanobiotechnology meets
Birbaum, K.; Brogioli, R.; Schellenberg, M.; Martinoia, E.; Stark, W. J.; Günther, D.;
Oberdorster, E., Manufactured nanomaterials (fullerenes, C60) induce oxidative stress in
Husen, A.; Siddiqi, K. S., Carbon and fullerene nanomaterials in plant system. J
Matsumoto, M.; Serizawa, H.; Sunaga, M.; Kato, H.; Takahashi, M.; Hirata-Koizumi, M.;
19 ACS Paragon Plus Environment
Journal of Agricultural and Food Chemistry
415
doses of single-wall or multi-wall carbon nanotube in rats. The Journal of toxicological sciences
416
2012, 37, 463-474.
417
43.
418
damaged DNA in rats exposed by oral gavage to C60 fullerenes and single-walled carbon
419
nanotubes. Environmental health perspectives 2009, 117, 703–708.
420
44.
421
nanotubes in biological samples through microwave-induced heating. Carbon 2012, 50, 4441-
422
4449.
423
45.
424
F.; Carriere, M., Accumulation, translocation and impact of TiO2 nanoparticles in wheat
425
(Triticum aestivum spp.): Influence of diameter and crystal phase. Sci. Total Environ. 2012, 431,
426
197-208.
427
46.Long, S.P.; Zhu, X.; Naidu,S. L.;Ort, D.R.,Can improvement in photosynthesis increase crop
428
yield. Plant, Cell and Environment (2006) 29, 315-330
429
47. Evans, J.R., Improving photosynthesis. Plant Physiol. 2013, 162:1780-1793
Page 20 of 37
Folkmann, J. K.; Risom, L.; Jacobsen, N. R.; Wallin, H.; Loft, S.; Moller, P., Oxidatively
Irin, F.; Shrestha, B.; Cañas, J. E.; Saed, M. A.; Green, M. J., Detection of carbon
Larue, C.; Laurette, J.; Herlin-Boime, N.; Khodja, H.; Fayard, B.; Flank, A.-M.; Brisset,
430 431 432 433 434 435 436 437 20 ACS Paragon Plus Environment
Page 21 of 37
438
Journal of Agricultural and Food Chemistry
Figure Captions
439 440
Figure 1. Experiment design focused of monitoring effects of long-term exposure of crop
441
species (barley, corn, and soybean) to MWCNT through cultivation in hydroponics system
442
supplemented with MWCNT. Experimental stages involved the preparation of hydroponics
443
solution, cultivation stage (20 weeks), and the bio-effects monitoring stage.
444 445
Figure 2. Average Photosynthetic light-response curves for MWCNTs treated and non-treated
446
corn (A) and soybean (B) plants growing in hydroponic systems supplemented with MWCNT.
447
These curves are the average of four plant measurement. All the measurements were conducted
448
at 400 ppm CO2 and ~25°C. *, p
