91 research outputs found
Turning earthworms into moonworms: Earthworms colonization of lunar regolith as a bioengineering approach supporting future crop growth in space
The earthworms beneficial effects on soils may be promising to improve lunar soil fertility,
enabling the use of local substrates for space farming. Herein, we investigated the effects of the
lunar regolith simulant (LHS-1) at different concentrations in cow manure mixtures on the survival
and fitness of Eisenia fetida. During 14 and 60-day experiments, although E. fetida showed an
increased mortality with LHS-1 alone, most of the population survived. More numerous tunnels
were observed when exposed to the higher concentrations of LHS-1 (poor in nutrients for
earthworms). This may be related to an increased mobility for food search. The cocoons production
was not affected by different substrate treatments, except for the highest concentration of
LHS-1. No effects of different LHS-1 concentrations on the amount of ingested substrate were
recorded. This study shows that E. fetida can potentially colonize lunar regolith representing a
future valuable biological tool for supporting crops growth on the Moon
Molecular analysis of a sunflower gene encoding an homologous of the B subunit of a CAAT binding factor
A genomic DNA fragment containing the
complete LEAFY COTYLEDON1-LIKE (HaL1L) gene was
retrieved by chromosome walking. Its sequence was confirmed
and elongated by screening a sunflower genomic
DNA BAC Library. HaL1L, whose cDNA had already
been sequenced and characterized, encodes a NF-YB subunit
of a CCAAT box-binding factor (NF-Y) involved in
the early stages of zygotic and somatic embryogenesis in
the Helianthus genus. In the HaL1L 50-flanking region,
elements specific to a putative TATA-box promoter and
two ââCG islesââ were identified. An investigation of the
methylation status of these CG rich DNA regions showed
that differentially methylated cytosines were recognizable
in the DNA of embryos on the fifth day after pollination in
comparison to leaf DNA suggesting that during plant
development epigenetic regulation of HaL1L transcription
was achieved by methylating cytosine residues. We also
searched the HaL1L nucleotide sequence for cis-regulatory
elements able to interact with other transcription factors
(TFs) involved in the HaL1L regulation. Of the elements
identified, one of the most intriguing is WUSATA, the
target sequence for the WUSCHEL (WUS) TF, which may
be part of a complex regulation network controlling
embryo development. In this article, we show that the
WUSATA target site, located in the intron of HaL1L, is
able to bind the TF WUS. Interestingly, we found auxin
and abscisic acid responsive motifs in the HaL1L promoter
region suggesting that this gene may additionally by under
hormonal control. Finally, the presence of a cytoplasmic
polyadenylation signal downstream to the coding region
indicates that this gene may also be controlled at the
translation level by a temporarily making the pre-synthesized
HaL1L mRNA unavailable for protein synthesis
Distinct mechanisms for aerenchyma formation in leaf sheaths of rice genotypes displaying a quiescence or escape strategy for flooding tolerance
Background and Aims Rice is one of the few crops able to withstand periods of partial or even complete submergence. One of the adaptive traits of rice is the constitutive presence and further development of aerenchyma which enables oxygen to be transported to submerged organs. The development of lysigenous aerenchyma is promoted by ethylene accumulating within the submerged plant tissues, although other signalling mechanisms may also co-exist. In this study, aerenchyma development was analysed in two rice (Oryza sativa) varieties, âFR13Aâ and âArborio Precoceâ, which show opposite traits in flooding response in terms of internode elongation and survival.
Methods The growth and survival of rice varieties under submergence was investigated in the leaf sheath of âFR13Aâ and âArborio Precoceâ. The possible involvement of ethylene and reactive oxygen species (ROS) was evaluated in relation to aerenchyma formation. Cell viability and DNA fragmentation were determined by FDA/FM4-64 staining and TUNEL assay, respectively. Ethylene production was monitored by gas chromatography and by analysing ACO gene expression. ROS production was measured by using Amplex Red assay kit and the fluorescent dye DCFH2-DA. The expression of APX1 was also evaluated. AVG and DPI solutions were used to test the effect of inhibiting ethylene biosynthesis and ROS production, respectively.
Key Results Both the varieties displayed constitutive lysigenous aerenchyma formation, which was further enhanced when submerged. âArborio Precoceâ, which is characterized by fast elongation when submerged, showed active ethylene biosynthetic machinery associated with increased aerenchymatous areas. âFR13Aâ, which harbours the Sub1A gene that limits growth during oxygen deprivation, did not show any increase in ethylene production after submersion but still displayed increased aerenchyma. Hydrogen peroxide levels increased in âFR13Aâ but not in âArborio Precoceâ.
Conclusions While ethylene controls aerenchyma formation in the fast-elongating âArborio Precoceâ variety, in âFR13Aâ ROS accumulation plays an important role
(Homo)glutathione Deficiency Impairs Root-knot Nematode Development in Medicago truncatula
Root-knot nematodes (RKN) are obligatory plant parasitic worms that establish and maintain an intimate relationship with their host plants. During a compatible interaction, RKN induce the redifferentiation of root cells into multinucleate and hypertrophied giant cells essential for nematode growth and reproduction. These metabolically active feeding cells constitute the exclusive source of nutrients for the nematode. Detailed analysis of glutathione (GSH) and homoglutathione (hGSH) metabolism demonstrated the importance of these compounds for the success of nematode infection in Medicago truncatula. We reported quantification of GSH and hGSH and gene expression analysis showing that (h)GSH metabolism in neoformed gall organs differs from that in uninfected roots. Depletion of (h)GSH content impaired nematode egg mass formation and modified the sex ratio. In addition, gene expression and metabolomic analyses showed a substantial modification of starch and Îł-aminobutyrate metabolism and of malate and glucose content in (h)GSH-depleted galls. Interestingly, these modifications did not occur in (h)GSH-depleted roots. These various results suggest that (h)GSH have a key role in the regulation of giant cell metabolism. The discovery of these specific plant regulatory elements could lead to the development of new pest management strategies against nematodes
Applications of lignin in the agri-food industry
Of late, valorization of agri-food industrial by-products and their sustainable utilization is
gaining much contemplation world-over. Globally, 'Zero Waste Concept' is promoted with
main emphasis laid towards generation of minimal wastes and maximal utilization of plantbased
agri-food raw materials. One of the wastes/by-products in the agri-food industry are the
lignin, which occurs as lignocellulosic biomass. This biomass is deliberated to be an
environmental pollutant as they offer resistance to natural biodegradation. Safe disposal of this
biomass is often considered a major challenge, especially in low-income countries. Hence, the
application of modern technologies to effectively reduce these types of wastes and maximize
their potential use/applications is vital in the present day scenario. Nevertheless, in some of the
high-income countries, attempts have been made to efficiently utilize lignin as a source of fuel, as a raw material in the paper industry, as a filler material in biopolymer based packaging and
for producing bioethanol. However, as of today, agri-food industrial applications remains
significantly underexplored. Chemically, lignin is heterogeneous, bio-polymeric, polyphenolic
compound, which is present naturally in plants, providing mechanical strength and rigidity.
Reports are available wherein purified lignin is established to possess therapeutic values; and
are rich in antioxidant, anti-microbial, anti-carcinogenic, antidiabetic properties, etc.
This chapter is divided into four sub-categories focusing on various technological
aspects related to isolation and characterization of lignin; established uses of lignin; proved
bioactivities and therapeutic potentials of lignin, and finally on identifying the existing research
gaps followed by future recommendations for potential use from agri-food industrial wastes.Theme of this chapter is based on our ongoing project- Valortech,
which has received funding from the European Unionâs Horizon 2020 research and innovation
program under grant agreement No 810630
'Crystallization and melting behaviour of a main-chain thermotropic copolyester
The crystallization and melting behavior of a main-chain thermotropic copolyester has been investigated by differential scanning calormetry (DSC). The effect of annealing time and temperature on the transition temperatures and enthalpies has been evidenced. Two melting peaks are observed and the first one clearly develops on annealing. Hypotheses are suggested about the crystallization mechanism
The Oxidative Paradox in Low Oxygen Stress in Plants
Reactive oxygen species (ROS) are part of aerobic environments, and variations in the availability of oxygen (O2) in the environment can lead to altered ROS levels. In plants, the O2 sensing machinery guides the molecular response to low O2, regulating a subset of genes involved in metabolic adaptations to hypoxia, including proteins involved in ROS homeostasis and acclimation. In addition, nitric oxide (NO) participates in signaling events that modulate the low O2 stress response. In this review, we summarize recent findings that highlight the roles of ROS and NO under environmentally or developmentally defined low O2 conditions. We conclude that ROS and NO are emerging regulators during low O2 signalling and key molecules in plant adaptation to flooding conditions
'Phase transitions of a main-chain thermotropic copolyester: crystallization, melting behaviour and glass-transition studied by DSC
The thermal behaviour of a main-chain thermotropic co-polyester has been investigated by Differential Scanning Calorimetry. Crystallization and melting have been studied through the effect of the annealing time and temperature on the transition temperatures and enthalpies. Two melting peaks are observed, the first one clearly developping on annealing. Hypotheses are suggested about the crystallization mechanism. The glass-transition (rate-dependent) appears broadened and does not show hysteresis on heating and cooling through the transition temperature
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