Modification of pollen proteins induced by growth substances and fungicides

The present study investigated the effects of the fungicides benomyl, dodine and penconazole and the growth regulators CPPU and paclobutrazol on pollen germination and tube growth, the microtubular organization of pollen tubes and total pollen polypeptides in the apple cvs Golden Delicious and Red Delicious. Each chemical showed a specific effect in at least one of the assayed functions. The fungicides confirmed their inhibitory effect on pollen germinaton. The most marked effects were recorded in both cultivars for dodine and benomyl when applied at field rates; penconazole showed a stronger inhibition in Golden Delicious than in Red Delicious when applied at field rate. By contrast, the tested growth regulators exerted a slight promotion of pollen germination. CPPU seemed not to alter the microtubular organization in Golden Delicious when applied ar rates ranging from routine field concentration to as much as three times this dosage, while paclobutrazol induced an anomalous disposition of tubuline when applied ar triple the field rate. The three assayed fungicides produced polypeptide patterns in a different way when compared to their effect on pollen germination, The effects of these chemicals on pollen gene regulation needs to be elucidated as their mechanisms of action are in many cases still unknown

The effect of multiplication number in vitro on juvenility of kiwifruit plants (Actinidia deliciosa a. chev.)

Sometimes a longer juvenility phase is observed on micropropagated plants, in orchard, during the first two-three years after planting. The high number of multiplication in vitro of the same explants could influence this phenomenon. This study aimed to investigate anatomical and genetic modifications induced in kiwifruit plants by micropropagation. Trials were carried out using plants micropropagated and obtained by cuttings. Shoots of ‘Hayward’ clone H8 were cultured in vitro and multiplied 60, 30 and 8 times respectively. In vitro multiplication rate of the material which was subjected to 60 multiplications was constantly greater, and the number of plants obtained ready to acclimatization phase doubled in this case. Plant height, shape and size of leaves, tomentosity density and distribution, number and size of xylem vessels were evaluated and differed significantly. The characteristics of micropropagated plants resulted to be related to the number of in vitro cycles. The phenomena evolution will also be followed out in field condition until maturity to compare yield and fruit quality

Effects of spermidine synthase overexpression on polyamine biosynthetic pathway in tobacco plants

Transgenic tobacco plants overexpressing the Datura stramonium spermidine synthase (EC 2.5.1.16) cDNA were produced in order to understand the role of this gene in the polyamine metabolism and in particular in affecting spermidine endogenous levels. All the analysed transgenic clones displayed a high level of overexpression of the exogenous cDNA with respect to the endogenous spermidine synthase. No relationship was detected between the mRNA expression level of S-adenosylmethionine decarboxylase (SAMDC, EC 4.1.1.50), which did not change between the negative segregant control and the transgenic plants, and spermidine synthase, suggesting the existence of an independent regulatory mechanism for transcription of the two genes. The determination of enzyme activities indicated an increased spermidine synthase and S-adenosylmethionine decarboxylase activity, with the last being mainly recovered in the particulate fraction. ODC (ODC, EC 4.1.1.17) was the most active enzyme and its activity was equally distributed between the soluble and the particulate fraction, while ADC (ADC, EC 4.1.1.19) activity in the transgenic plants did not particularly change with respect to the controls. In comparison to the controls, the transformed plants displayed an increased spermidine to putrescine ratio in the majority of the clones assayed, while the total polyamine content remained almost unchanged. These findings suggest a high capacity of the transformed plants to tightly regulate polyamine endogenous levels and provide evidence that spermidine synthase is not a limiting step in the biosynthesis of polyamines

Organizzazione della filiera vivaistica e certificazione delle piante.

Le tecniche di moltiplicazione, l'uso del portinnesto, la micropropagazione: molti gruppi di ricerca in Italia sono attivi nel miglioramento dei sistemi di propagazione del nocciolo. Avanzano anche i lavori per lo sviluppo del programma di certificazione genetico sanitaria, su base volontaria, del materiale vivaistico che, alla luce del mutato quadro normativo europeo, dovrebbe essere operativo entro la fine del 2017

Circulating tumor cells and microemboli can differentiate malignant and benign pulmonary lesions

The presence of circulating tumor cells (CTC) or microemboli (CTM) in the peripheral blood can theoretically anticipate malignancy of solid lesions in a variety of organs. We aimed to preliminarily assess this capability in patients with pulmonary lesions of suspected malignant nature. We used a cell-size filtration method (ScreenCell) and cytomorphometric criteria to detect CTC/CTM in a 3 mL sample of peripheral blood that was taken just before diagnostic percutaneous CT-guided fine needle aspiration (FNA) or core biopsy of the suspicious lung lesion. At least one CTC/CTM was found in 47 of 67 (70%) patients with final diagnoses of lung malignancy and in none of 8 patients with benign pulmonary nodules. In particular they were detected in 38 (69%) of 55 primary lung cancers and in 9 (75%) of 12 lung metastases from extra-pulmonary cancers. Sensitivity of CTC/CTM presence for malignancy was 70.1% (95%CI: 56.9-83.1%), specificity 100%, positive predictive value 100% and negative predictive value 28.6% (95%CI: 11.9-45.3%). Remarkably, the presence of CTC/CTM anticipated the diagnosis of primary lung cancer in 3 of 5 patients with non-diagnostic or inconclusive results of FNA or core biopsy, whereas CTC/CTM were not observed in 1 patient with sarcoidosis and 1 with amarthocondroma. These results suggest that presently, due to the low sensitivity, the search of CTC/CTM cannot replace CT guided percutaneous FNA or core biopsy in the diagnostic work-up of patients with suspicious malignant lung lesions. However, the high specificity may as yet indicate a role in cases with non-diagnostic or inconclusive FNA or core biopsy results that warrants to be further investigated