Pierdomenico Perata

Plant responses to anaerobiosis

Plant life is greatly impaired under conditions of oxygen deficit. Only few plants can grow in waterlogged soils, thanks to anatomical adaptation allowing the transport of oxygen to the submerged parts of the plant. The behaviour of a few plant species able to germinate under completely anoxic conditions can be explained only by assuming that a biochemical adaptation is present in these species but absent in all the other species. Research on this subject has produced experimental evidence about the key role of carbohydrate mobilisation during anaerobic germination of rice grains, about the role of ethanol in anoxia-induced injuries, and more recently, about the genome-wide transcript profililing in anoxic Arabidopsis seedlings.

Signal transduction in plants: hormone and sugar sensing

The ability to sense sugars is crucial for the modulation of gene expression in plants. Despite the importance of this phenomenon, our knowledge of sugar sensing in plants is scant. Several valuable hypotheses have been put forward based on the extensive knowledge of sugar sensing in yeast. In recent years, tests of these hypotheses have shown that hexokinase and sucrose-non-fermenting- (SNF-) related proteins appear to be involved in sugar sensing and transduction, not only in yeast but also in higher plants. However, even if plants share with yeast some elements involved in sugar sensing, several aspects of sugar perception are likely to be peculiar to higher plants. Plants should be able to sense not only glucose but also other hexoses, Such as fructose and disaccharides (sucrose, maltose and others). We have shown that comparing the molecular requirements for sucrose transport with those for disaccharide sensing suggests that these sugars are perceived possibly at the plasma membrane level independently from sucrose transport. Evidence is provided of cross-talk between the sugar-sensing pathways and the physiology of plant hormones.

Crop physiology: source-sink relations in sugar beet

Sugar-beet plants accumulate sucrose in the root. This plant is of special interest for plant physiologists studying the physiology and biochemistry of plant carbohydrates. Sugar-beets should ideally display a flux of sucrose from the leaf system to the root. This is not always what is observed, and under particular growing conditions some sucrose stored in the root can be lost due to a backflow from the root to the leaves. This phenomena has negative economical consequences for the sugar-beet grower. We use molecular probes and enzymatic tests as markers of the source-sink status of the plant tissues, with the aim of elucidating the pathways of sucrose metabolism in open-fiels grown sugar-beet plants.

Phytoremediation of heavy-metal contaminated soils

Phytoremediation of contaminated soils is a hot topic, since plants are a robust and renewable resource. Hyperaccumulation of metals or metalloids seems to be essential for phytoextraction, and vacuolar sequestration is a key component conferring hypertolerance. Natural hyperaccumulators as model plants can be studied in order to enhance heavy metal accumulation and/or tolerance. Recent studies demonstrated that both good biomass yields and metal hyperaccumulation are required to make this process efficient, but accumulation of metals to high levels in plant species is often hampered by low biomass. Genetic engineering can help to overcome these limits, but more knowledge of the molecular mechanisms that underlie this process is however required before the traits can be transferred to high biomass plants. The pratical aspects of the use of hyperaccumulating plants need also further research. We examined the ability of Cannabis sativa to take up and tolerate Cu salts from a nutrient solution. By means of electron microscopy and X-ray microanalysis, we observed Cu accumulation in upper leaf epidermal cells, in spiculae and in abaxial trichomes. No traces of this metal was found in epidermal cells of the stem. Even if Cannabis seems not to have evolved a specific tolerance and accumulation mechanisms, it shows to have a considerable potential for phytoremediation purposes. It is able to transfer Cu from the root to the shoot, one of the criteria that must be met to consider a plant well suited for phytoremediation. Moreover the fibres seem not to be affected by Cu contamination, allowing them to be collected and used with economical advantage.

Fortification of plant crops with iodine

Iodine deficiency is common throughout the less developed world, resulting in cretinism, goitre, immune incompetence and learning disabilities. Food supplements (e.g. iodized salts) are effective in some parts of the world, but fail in less developed countries because of infrastructure problems. Field fortification is therefore considered desirable. However, iodine leaches readily from soils and its content in most soils is generally low. Plants take up iodine, but crop species show variable efficiency in this ability. For example Brassica napus shows a good ability to take up iodine, while Lycopersicon esculentum and Oryza sativa can take up iodine with lower efficiency. Iodization of irrigation water have been shown to contribute to reducing iodine deficiency disorders. The aim of the project is to provide new technologies to increase the iodine content in plants. This goal will be achieved through an integrated approach including the study of iodine uptake in plants, the development of a protocol for the treatment of crop plants with iodine applied as a leaf spray, and the production of transgenic plants overexpressing the human sodium iodide symporter. Preliminary experimental evidence suggests that potato plants treated with iodine salt can increase significantly their iodine content in the tubers. (Download the paper "in Italian- "Lo iodio nell'alimentazione umana ed il ruolo delle colture erbacce").

High-anthocyanin tomatoes

Tomato (Solanum lycopersicon L.) is cultivated all over the world as annual crop (for few months up to nearly the whole year) in open field and under greenhouse conditions for both fresh consumption and industrial processing (canned products, fruit juice, etc.). The nutraceutical properties of tomato are mainly related to the antioxidant potential of tomato, which in turn is due to the presence of a mix of antioxidant bio-molecules like lycopene, ascorbic acid, phenolics, flavonoids and vitamin E. On the other hand, tomato fruits do not normally contain significant concentration of anthocyanins, substances with a well known nutraceutical value.
The aim of this research project is the production of high-anthocyanin containing tomatoes.
In order to achieve this goal, the project will take advantage of the joint efforts of researchers well qualified in horticulture, crop physiology, genetics and breeding.
More in detail, these are the objectives of the project:

• to investigate the influence of growing conditions, including cultivation season and the salinity of irrigation water, on the accumulation of anthocyanins and other pigments in the fruits of selected genotypes of Solanum lycopersicon.
• the description of the physiology of anthocyanin synthesis in tomato, including the identification of regulatory genes as well as genes encoding for the enzymes involved in the anthocyanin biosynthetic pathways. Furthermore, the effects of sugars and of plant hormones will also be investigated. This information will be used as tools in breeding as well as for establishing optimal growth conditions to enhance anthocyanin synthesis in tomato.
• the creation of tomato breeding lines which possess a high anthocyanin content in the plant as well as in the fruit, by combining monomendelian mutants differing in the anthocyanin content of the plant and the fruit.
• the identification of suitable molecular markers to support the breeding activities.
• the identification of the role of anthocyanins in the response to biotic (Xanthomonas campestris pv vesicatoria; Alternaria) and abiotic (chilling, salinity) stress.

Scuola Estiva di Orientamento Volterra 2008

Sfida intellettuale (file ppt, 100 kb)
Sfida intellettuale (file pdf, 3,4 Mb)

Corso di Biotecnologie Vegetali

Master universitario di primo livello in valorizzazione e controllo delle produzioni agro alimentari

Introduzione alle biotecnologie 1 (file ppt, 284 kb)
Introduzione alle biotecnologie 2 (file pdf, 696 kb)
Biotecnologie applicate alla difesa da insetti (file pdf, 1.535 kb)
Biotecnologie applicate alla difesa da virus (file pdf, 989 kb)
Biotecnologie applicate alla floricoltura (file pdf, 275 kb)
Biotecnologie applicate alla maturazione dei frutti (file pdf, 679 kb)
Biotecnologie applicate al diserbo (file pdf, 1.440 kb)
Biotecnologie applicate alla nutrizione e bioindustriali (file pdf, 644 kb)

Crop Physiology

International Doctoral Scholarships in Agrobiodiversity

Crop Physiology: Sugarbeet (file ppt, 456 kb)
Crop Physiology Sugarbeet flowering (file pdf, 4.028 kb)
Crop Physiology Phytoremediation (file pdf, 3.892 kb)
Crop Physiology Iodine (file pdf, 1.246 kb)

Corso Fisiologia Vegetale Applicata

Fisiologia Post Raccolta (file ppt, 4.091 kb)

Corso "How to Publish in International Science Journals"

How to publish in International Science Journals (file ppt, 4.446 kb)

• Articolo sulla "Genomica e Post-genomica delle Piante" su rivista DARWIN" (Download file)
• Articolo su "Sun black" sul quotidiano Il Tirreno (Download file)
• Fotografie del pomodoro "Sun Black" (foto: 1, 2, 3, 4)
• Articolo sulla sintesi degli antociani in pomodoro (Rivista "Agronomica") (Download file)
• Servizio su "Sun black" di Studio Aperto (video)
• Servizio su "Sun black" del TG1 (video)
• Servizio su "Sun black" del TG3 (video)
• Servizio su "Sun black" di Uno Mattina (video)