48 research outputs found
Expression of Spcdc25 and Arath;WEE1 in Arabidopsis alters the response of hypocotyl explants to auxin & cytokinin in culture
No full textSimultaneous characterisation of Prunus persica L. fruit volatilome and gene expression profile for a better understanding of molecular mechanisms underlying changes of peach during post-harvest storage
No full textIn Arabidopsis thaliana Cd differentially impacts on hormone genetic pathways in the methylation defective ddc mutant compared to wild type
No full textDNA methylation plays an important role in modulating plant growth plasticity in response to stress, but mechanisms involved in such control need further investigation. We used drm1 drm2 cmt3 mutant of Arabidopsis thaliana, defective in DNA methylation, to explore metabolic pathways downstream
epigenetic modulation under cadmium (Cd) stress. To this aim, a transcriptomic analysis was performed on ddc and WT plants exposed to a long-lasting (21 d) Cd treatment (25/50 μM), focusing on hormone genetic pathways. Growth parameters and hormones amount were also estimated.
Transcriptomic data and hormone quantification showed that, under prolonged Cd treatment, level and signalling of growth-sustaining hormones (auxins, CKs, GAs) were enhanced and/or maintained,
while a decrease was detected for stress-related hormones (JA, ABA, SA), likely as a strategy to avoid the side effects of their long-lasting activation. Such picture was more effective in ddc than WT, already at 25 μM Cd, in line with its better growth performance. A tight relationship between
methylation status and the modulation of hormone genetic pathways under Cd stress was assessed. We propose that the higher genome plasticity conferred to ddc by DNA hypomethylated status underlies its prompt response to modulate hormones genetic pathways and activity and assure a flexible growth
Molecular and cytophysiological events underlying ectopic morphogenesis (epiphylly) in a somaclonal variant of interspecific hybrid Helianthus annuus L. x H. tuberosus
No full textCadmium affects cell niches maintenance in Arabidopsis thaliana post-embryonic shoot and root apical meristem by altering the expression of WUS/WOX homolog genes and cytokinin accumulation
No full textCadmium (Cd) is one of the most widespread polluting heavy metals in both terrestrial and aquatic environments and represents an extremely significant pollutant causing severe environmental and social problems due to its high toxicity and large solubility in water.
In plants, the root is the first organ that get in contact with Cd. It is absorbed by the root system and translocated to the shoot and leaves through xylem loading, causing a variety of genetic, biochemical, and physiological damages. Cd inhibits both the root and shoot growth, but the mechanisms underlying this inhibition remain elusive.
In this context in the present work we focused the attention on the effects of Cd on meristem size and organization of both shoot and root . To this aim morpho-histological and molecular analyses were carried out on 5 days old seedlings exposed or not to Cd (100 μM and 150 μM for 24) of wild type and transgenic lines expressing molecular markers with an important role in shoot and root pattern organization.
More precisely, we monitored the expression pattern of WUS/CLV3 and WOX5 transcription factors involved in the establishment and maintenance of stem cell niche and the control of meristem size and of TCSn::GFP cytokinin-sensitive sensor as relevant components of hormone circuit controlling shoot and root growth.The results highlighted that the treatments with Cd impacts shoot and root size and shape by altering the paralogous WOX genes expression via cytokinin accumulation
Augmented analysis of sensorial, volatilome and gene expression data from peach cultivars during cold storage to identify markers for fruit quality
No full textPeach (Prunus persica (L. Batsch) produces high quality but perishable fruit appreciated for their
distinctive aroma, and other organoleptic qualities including sweetness, colour, and texture
which vary across different cultivars. Peaches are produced commercially in warmer temperate
regions such as Southern Europe, and frequently exported to Northern Europe. Due to the long
travel distances and complex supply chains peach fruit are transported cold to delay ripening
and spoilage. However long periods of cold storage can result in chilling injury and loss of quality.
Our understanding of how cold storage affects quality across different varieties can be explored
through different approaches. Here effects were assessed in one peach ('Sagittaria') and one
nectarine cultivar ( 'Big Top') through volatilome fingerprinting combined with gene expression
profiling. For analysis of the volatile organic compounds (VOCs) contributing to the volatilome,
we applied two-dimensional gas chromatography (GC×GC) combined with time-of-flight mass
spectrometry (TOF-MS), as well as sensorial analysis. RNA-sequencing was applied to identify
differentially expressed genes (DEGs) during post-harvest storage focusing on genes associated
with VOCs. Peach fruits were analysed at harvest and during 14 days of cold storage at 1°C.
Different numbers of VOCs were identified in the two cultivars: of 159 from ‘Sagittaria’, and 89
from ‘Big Top’ fruit. Canonical Analysis of Principal coordinates (or CAP) was able to discriminate
amongst VOC profiles from the two cultivars and across post-harvest storage time points. A
multitrait analysis of sensory, VOC and gene expression data supported the analysis based only
on VOCs showing correlations between the expression profiles of VOC-related genes and VOC
abundance. These data are of potential use to peach breeders for improving cold storage
resilience in relation to sensory changes, and could form the basis for markers of use in assessing
fruit quality through the supply chain
Fruit volatilome profiling through GC × GC-ToF-MS and gene expression analyses reveal differences amongst peach cultivars in their response to cold storage
No full textPeaches have a short shelf life and require chilling during storage and transport. Peach aroma is important for consumer preference and determined by underlying metabolic pathways and gene expression. Differences in aroma (profiles of volatile organic compounds, VOCs) have been widely reported across cultivars and in response to cold storage. However, few studies used intact peaches, or used equilibrium sampling methods subject to saturation. We analysed VOC profiles using TD‑GC × GC‑ToF‑MS and expression of 12 key VOC pathway genes of intact fruit from six cultivars (three peaches, three nectarines) before and after storage at 1 °C for 7 days including 36 h shelf life storage at 20 °C. Two dimensional GC (GC × GC) significantly enhances discrimination of thermal desorption gas chromatography time‑of‑flight mass spectrometry (TD‑GC‑ToF‑MS) and detected a total of 115 VOCs. A subset of 15 VOCs from analysis with Random Forest discriminated between cultivars. Another 16 VOCs correlated strongly with expression profiles of eleven key genes in the lipoxygenase pathway, and both expression profiles and VOCs discriminated amongst cultivars, peach versus nectarines and between treatments. The cultivar‑specific response to cold storage underlines the need to understand more fully the genetic basis for VOC changes across cultivars
The KNOTTED-like genes of peach (Prunus persica L. Batsch) are differentially expressed during drupe growth and the class 1 KNOPE1 contributes to mesocarp development
No full textThe KNOTTED-like transcription factors (KNOX) contribute to plant organ development. The expression patterns of peach KNOX genes showed that the class 1 members act precociously (S1-S2 stages) and differentially during drupe growth. Specifically, the transcription of KNOPE1 and 6 decreased from early (cell division) to late (cell expansion) S1 sub-stages, whilst that of STMlike1, 2, KNOPE2, 2.1 ceased at early S1. The KNOPE1 role in mesocarp was further addressed by studying the mRNA localization in the pulp cells and vascular net at early and late Si. The message signal was first diffuse in parenchymatous cells and then confined to hypodermal cell layers, showing that the gene down-tuning accompanied cell expansion. As for bundles, the mRNA mainly featured in the procambium/phloem of collateral open types and subsequently in the phloem side of complex structures (converging bundles, ducts). The KNOPE1 overexpression in Arabidopsis caused fruit shortening, decrease of mesocarp cell size, diminution of vascular lignification together with the repression of the major gibberellin synthesis genes AtGA20ox1 and AtGA3ox1. Negative correlation between the expression of KNOPE1 and PpGA3ox1 was observed in four cultivars at S1, suggesting that the KNOPE1 repression of PpGA3ox1 may regulate mesocarp differentiation by acting on gibberellin homeostasis
Volatilome fingerprinting, transcriptomics and sensorial analysis of peach cultivars during cold storage: A multi-trait approach to identify predictive markers of food quality
No full textFruit quality is a key driver for consumers. Therefore, it is important to optimize product quality throughout the supply chain. Quality can be assessed visually through fruit colour and firmness, while sensorial analyses provide data on aroma, sweetness and acidity. However, fingerprinting the volatilome (the volatile organic compound (VOC) profile) combined with global analyses of gene expression profiles, through next generation sequencing, are useful tools for objective quality assessment. These can provide data related to the cultivar, and its growth location and post-harvest treatments. Peach (Prunus persica (L. Batsch) fruits deteriorate rapidly at ambient temperature therefore cold storage is widely used to delay post-harvest ripening of the fruit, however they also suffer from cold stress.
Here, the volatilome of one peach (cv. Sagittaria) and one nectarine (cv Big Top) was analysed using comprehensive two-dimensional gas chromatography (GC×GC) and time-of-flight mass spectrometry (TOF-MS). In parallel RNA-sequence transcriptomics was used to identify differentially expressed genes (DEGs) associated with VOC metabolism. Fruits were analysed at harvest, and after 1, 5, 7 and 14 days of storage at 1°C.
We identified 159 and 89 VOCs from cv. Sagittaria, and cv. Big Top fruit respectively. VOC profiles showed discrimination both between the cultivars and amongst post-harvest storage periods, when analysed using Canonical Analysis of Principal coordinates (CAP). Sensory evaluation supported results from the volatilome. Gene expression analysis of VOC-related genes also showed a good correlation with changes in VOCs profiles.
Overall Omics data from VOC profiles and gene expression, may be of value to breeders in their selection of specific traits relating to aroma and post-harvest resilience. These technologies can also have a potential value throughout the supply chain in developing objective diagnostic tests to monitor quality from producer to consumer
Identification of potential molecular markers for detection of lengthy chilled storage of Prunus persica L. fruit
No full textLow temperature is the main strategy to preserve fruit quality post-harvest, in the supply chain. Low temperatures reduce the respiration, ethylene emission, and enzymatic activities associated with senescence. Unfortunately, peaches are sensitive to low temperatures if exposed for long periods, resulting in physiological disorders that can compromise commercial quality. Maximum damage occurs at 5 °C while at 1 °C damage is reduced. Therefore, rapid early detection methods for the distribution chain to monitor length and temperature of fruit storage are needed. The aim of this work was to identify candidate genes to develop an antibody-based marker system in peach fruit to monitor chilled storage. Two cultivars were tested: ‘Sagittaria’, an early ripening peach, and ‘Big Top’ a mid-season ripening nectarine, with delayed softening and resistance to supply-chain conditions. Both cultivars were subjected to 1 or 5 °C chilled storage for different times to simulate typical supply-chain conditions. Identification and expression of potential marker genes was assessed using a previous transcriptomic study following storage at 1 °C. Fifteen candidate genes were selected, however only seven proteins encoded were suitable as protein markers as they lack a transmembrane domain. Real-time qPCR using fruit from the subsequent year to the transcriptome was used to assess expression at both 1 and 5 °C chilled storage of five candidate genes. Four genes and the related proteins were identified that would be suitable for the development of molecular markers: a Pathogenesis-Related Bet v I family protein, a dehydrin, a Glycosyl hydrase family 18 protein and a Late Embryogenesis abundant protein
