Although table grape is a non-climacteric fruit with low physiological activity, it is however prone to weight loss, softening and fungal infection during postharvest period. The whole vine ...especially fruits were sprayed with putrescine (put; 0, 1, 2 mM), spermidine (spd; 0, 1, 2 mM) at 40 and 20 days before harvest. Different fruit characteristics were analyzed after harvest and remaining fruits were stored at 1.5±1°C and 90±5% RH for 25 and 55 days. Different concentrations of polyamines significantly increased firmness of grapes at harvest. Firmness was also retained and decreased weight loss of fruit during storage. Table grape storability could be extended by put and spd treatments due to their significant effect on delaying the softening, water loss, fungal infection and senescence.
The aim of this study was to assess the effects of spermidine (Spd) on ameliorating adverse effects of salinity
in Troyer citrange seedlings. For this purpose, 6-month-old, uniform-sized seedlings of ...Troyer citrange were transplanted
to plastic containers containing Hoagland nutrient solution. Addition of 75mMNaCl into the nutrient solution reduced
the plant growth, leaf chlorophyll content, chlorophyll Zuorescence yield (Fv/Fm), net photosynthetic rate, respiration
rate, and total Spd, N, and $Ca^ {2+}$ + $Mg^ {2+}$ contents of the leaves. It increased the leaf proline, total putrescine (Put), total
spermine (Spm), $Na^ +$, and Cl- contents of the leaves. Addition of Spd (0.1 or 0.5 mM) to the saline nutrient solution and
its weekly sprays (1 or 5 mM) on NaCl-stressed plants improved leaf number, chlorophyll content, Fv/Fm, net
photosynthetic rate, and N content; increased total Spd and Spm contents; and reduced $Na^ +$ contents of the plants. Leaf
$Ca^ {2+}$ + $Mg^ {2+}$contents were slightly improved only when Spd (0.5 mM) was added to the saline nutrient solution. Leaf P
and K+ contents were not significantly affected by the salinity or Spd treatments. Among the polyamines, Put content was
least affected, while there was a sharp increase in Spm content due to the salinity and Spd treatments. These results
suggest involvement of Spm in the salinity tolerance of citrus rootstock Troyer citrange.
Buds from newly developed shoots obtained from forced outgrowth of mature field-grown hybrid hazelnut trees (Corylus avellana L.) were cultured in vitro on Murashige and Skoog MS (1962) medium and a ...modified Driver and Kuniyuki DKW (1984) medium containing 6.7 µM, 11.1 µM or 15.5 µM of N-6 benzyladenine (BA) supplemented with or without a combination of polyamines (0.2 mM of putrescine + 0.2 mM of spermidine + 0.05 mM of spermine). The effects of culture medium and BA were found to be insignificant on explant response. Polyamines were found to have a strong effect on both shoot elongation and on number of buds per shoot. Polyamines stimulated mean shoot elongation by 83% and increased the mean number of buds per shoot by 41% compared to when they were not used. In the presence of polyamines, shoot elongation continued up to 4.0 cm while in the absence of polyamines shoot elongation only reached 2.0 cm. Results indicate that polyamines in the culture medium could ease the establishment of cultures and enhance the morphogenic capacity of mature explants.
Bu çalışmada, spermidin (Spd), spermin (Spm) ve sikloheksilamin'nin (CHA), diploid (Triticum monococcum L.), tetraploid (T. durum Desf.) ve heksaploid (T. aestivum L.) buğdaylarda tohum çimlenmesi, ...kök uzaması, mitotik indeks ve kromozomların davranışına etkileri incelendi. Poliaminler üç türde de tohum çimlenmesini inhibe etti. CHA diploidlerde ve tetraploidlerde tohum çimlenmesini inhibe ederken, heksaploidlerde çimlenmeyi teşvik etti.
Spd, Spm ve CHA üç türün kök uzamasını inhibe etti. Spd ve Spm diploidlerde ve tetraploidlerde mitotik indekste inhibisyona neden olurken, heksaploidlerde Spd artışa, Spm ise düşüşe neden oldu. CHA üç türün kök uçlarında da mitoz bölünme frekansını düşürdü. Her üç türün kontrol grubunda da mitotik anormallikler gözlendi. Bu anormallikler bozuk metafaz tablası, anafazda kromozom köprüleri, eşit olmayan dağılım, geç kalan kromozomlar, çok kutuplu iğ ipliği şeklinde özetlenebilir. Spd, Spm ve CHA üç türde de anormallik yüzdesini etkiledi. Sonuçlar, kök uzamasındaki inhibisyonun bu maddelerin mitotik indeksi düşürmelerinden kaynaklandığını gösterdi.
The effects of spermidine (Spd), spermine (Spm) and cyclohexylamine (CHA) on seed germination, root elongation, mitotic index and chromosomal behavior were studied in diploid (Triticum monococcum L.), tetraploid (T. durum Desf.) and hexaploid (T. aestivum L.) wheats. The polyamines (PA) inhibited seed the germination in three species. CHA inhibited seed germination in diploid and tetraploid species, but it showed a stimulation in hexaploid seeds. Spd, Spm and CHA reduced root elongation in three species. Spd and Spm decreased mitotic index in diploids and tetraploids. In hexaploids, Spd slightly increased the division frequency whereas Spm decreased it. The root tips of the three species treated with CflA showed maximum inhibition in mitotic index. Some mitotic abnormalities like unoriented metaphase, anaphase bridges, unequal distribution, laggards, multipolar spindle fibers were observed in the control groups of diploid, tetraploid and hexaploid. Spd, Spm and CHA affected the percentages of aberrations. Our results suggested that the reason of the inhibition in root elongation was due to the reduction in the mitotic index.
Poplar shoots raised
in vitro rooted by 100 °lo in the presence of an auxin while in its absence they did not root. Putrescine, however, and the inhibitor of spermidine synthase, cyclohexylamine ...(CHA), which favours putrescine accumulation, were able to promote up to 40 % rooting in the absence of auxin. The inhibitory effect of aminoguanidine (AG), which inhibits diamine oxidase, indicated that the catabolic pathway of putrescine was involved in the rooting process. The inductive phase of rooting in poplar shoots was characterized by an increase of peroxidase activity followed by a rapid decrease. Putrescine and CHA favoured this variation. AG and spermidine had adversary effects.
