One Heat Shock Transcription Factor Confers High Thermal Tolerance in Clematis Plants

Clematis plants play an important role in botanical gardens. Heat stress can destroy the activity, state and conformation of plant proteins, and its regulatory pathway has been well characterized in Arabidopsis and some crop plants. However, the heat resistance response mechanism in horticultural plants including Clematis has rarely been reported. Here, we identified a heat-tolerant clematis species, Clematis vitalba. The relative water loss and electrolytic leakage were significantly lower under heat treatment in Clematis vitalba compared to Stolwijk Gold. Differential expression heat-tolerant genes (HTGs) were identified based on nonparametric transcriptome analysis. For validation, one heat shock transcription factor, CvHSF30-2, extremely induced by heat stimuli in Clematis vitalba, was identified to confer tolerance to heat stress in Escherichia coli and Saccharomyces cerevisiae. Furthermore, silencing of HSF30-2 by virus-induced gene silencing (VIGS) led to heat sensitivity in tobacco and Clematis, suggesting that the candidate heat-resistant genes identified in this RNA-seq analysis are credible and offer significant utility. We also found that CvHSF30-2 improved heat tolerance of Clematis vitalba by elevating heat shock protein (HSP) expression, which was negatively regulated by CvHSFB2a. Taken together, this study provides insights into the mechanism of Clematis heat tolerance and the findings can be potentially applied in horticultural plants to improve economic efficiency through genetic approaches.

SADRŽAJ METALA U ZEMLJIŠTU I ODABRANIM BILJKAMA NA JALOVIŠTU FLOTACIJE RUDNIK DOO „RUDNIK"

The aim of this study was to determine the concentration of some metals (Ca, Mg, Mn, Fe, Zn, Ni, Cr, Cd) in the soil and species of Tussilago farfara L. and Clematis vitalba L. on the tailings and flotation of the mine DOO "Rudnik". Concentrations in the soil were: Pb and Cu - higher than the maximum allowed, limit and remediation values; Cd, Cr and Ni - higher than the maximum allowed and limit values, and Zn higher than the limit values (according to the regulations of the Republic of Serbia). Better bioaccumulation of all tested metals was shown by T. farfara species, especially leaves for Zn. The results indicate the possible use of aboveground parts of both plant species in the revitalization of tailings by bioaccumulation of tested metals.

Mixed mesophilic mountain beech forest (Fagetum submontanum serbicum) on the Vidlič Mountain

On the Vidlič mountain, mixed mesophilic mountain beech forests (Fagetum submontanum serbicum) have been recorded at altitudes of 700 - 1000 m, at the following localities: Crni vrh, Vazganica, Kranjci, Planinarski dom, and Visočka Ržana. Phytocenological research was performed on the mentioned localities by the Braun-Blanquet method (Braun-Blanquet, 1964). It was taken 11 phytocenological plots. Beech (Fagus moesiaca) and turkey oak cer (Quercus cerris) were the main edificators and have the highest degree of presence in the examined phytocenoses on the tree floor. In the floor of shrubs, the following species: Viburnum lantana, Crataegus monogyna, Rosa canina, Daphne mezereum, Clematis vitalba, and Ligustrum vulgare have been noticed with the highest degree of presence. Acer campestre has been dominated with the highest degree from the shoots of trees. In the floor of herbaceous plants, the species: Viola alba, Cruciata glabra, Brachypodium sylvaticum, Euphorbia amygdaloides, Helleborus odorus, Fragaria vesca were with the highest degree of presence.

Effects of desiccation of seeds in nine species with morphophysiological dormancy on germination and embryo growth

Aims In species with morphophysiological seed dormancy (MPD), little is known about the effects of desiccation of imbibed seeds on embryo growth and germination. We studied seed responses to dehydration in nine species with different levels of MPD. Methods For each species, a control test was conducted by keeping seeds permanently hydrated and exposed to the optimal stratification-incubation sequence to promote embryo growth. Simultaneously, tests were run in which seed stratification was interrupted for 1 month by desiccation at room temperature. Important Findings In Clematis vitalba and Ribes alpinum, with nondeep simple MPD, desiccation affected neither embryo growth nor seed viability, but the desiccation led to a decrease of germinative ability in R. alpinum by 16%. The seeds of Narcissus pseudonarcissus subsp. munozii-garmendiae, with deep simple epicotyl MPD, tolerated desiccation in different embryo growth stages, but their germinative ability decreased slightly. The response of species with complex levels of MPD to desiccation was more variable: Delphinium fissum subsp. sordidum, with intermediate complex MPD, and Anthriscus sylvestris and Meum athamanticum, both with deep complex MPD, tolerated desiccation. In contrast, Ribes uva-crispa with nondeep complex MPD, Lonicera pyrenaica with intermediate complex MPD, and Chaerophyllum aureum with deep complex MPD, had diminished germination ability by desiccation. Although seeds of the species with simple levels of MPD tolerated desiccation, those of some species with complex levels were also highly tolerant. Thus, desiccation did not induce secondary dormancy in late embryo growth stages. The desiccation tolerance of imbibed seeds of most of the nine species may show their adaptability to climate change in the Mediterranean region.

New Alien Plant Species Recorded in South Lithuania

Performing a thorough inventory of alien plant species in the southern part of Lithuania, we found twelve alien plant species previously not registered in the country: Aruncus dioicus, Buxus sempervirens, Clematis vitalba, Clematis recta, Colutea arborescens, Erechtites hieraciifolius, Erigeron strigosus, Euphorbia marginata, Genista sagittalis, Lathyrus latifolius, Sempervivum arachnoideum and Silphium perfoliatum. All newly recorded alien species, except Erechtites hieraciifolius and possibly Genista sagittalis, have been introduced intentionally and escaped from cultivation. Ten species currently occur as casuals, whereas Colutea arborescens and Genista sagittalis are locally naturalised. Naturalisation of Buxus sempervirens and Euphorbia marginata in the foreseen future is unlikely in Lithuania, naturalisation of Aruncus dioicus, Sempervivum arachnoideum and Silphium perfoliatum is possible. In contrast, naturalisation of the other five species is expected in the nearest future. Invasion of seven analysed alien species is unlikely in Lithuania, whereas Clematis vitalba, Colutea arborescens, Erechtites hieraciifolius, Erigeron strigosus, Lathyrus latifolius have the potential to become invasive in the country. Therefore, their reproduction and spread should be monitored, and measures for prevention of their invasion should be applied, if necessary.

Mechanical properties and structure–function trade-offs in secondary xylem of young roots and stems

Bending and torsional properties of young roots and stems were measured in nine woody angiosperms. The variation in mechanical parameters was correlated to wood anatomical traits and analysed with respect to the other two competing functions of xylem (namely storage and hydraulics). Compared with stems, roots exhibited five times greater flexibility in bending and two times greater flexibility in torsion. Lower values of structural bending and structural torsional moduli (Estr and Gstr, respectively) of roots compared with stems were associated with the presence of thicker bark and a greater size of xylem cells. Across species, Estr and Gstr were correlated with wood density, which was mainly driven by the wall thickness to lumen area ratio of fibres. Higher fractions of parenchyma did not translate directly into a lower wood density and reduced mechanical stiffness in spite of parenchyma cells having thinner, and in some cases less lignified, cell walls than fibres. The presence of wide, partially non-lignified rays contributed to low values of Estr and Gstr in Clematis vitalba. Overall, our results demonstrate that higher demands for mechanical stability in self-supporting stems put a major constraint on xylem structure, whereas root xylem can be designed with a greater emphasis on both storage and hydraulic functions.

Notes on invasive and expansive trees and shrubs

Expansion and invasion of plants indicate successful colonization and competitive abilities of species. There are fewer invasive and expansive woody plants than herbs. Main expansive (native species) trees and shrubs are Acer platanoides, Acer pseudoplatanus, Clematis vitalba, Crataegus sp. div., Fraxinus excelsior, Prunus spinosa, Rubus sp. div., Sambucus nigra. Main invasive (alien species) are Acer negundo, Ailanthus altissima, Amorpha fruticosa, Cytisus scoparius, Fraxinus pennsylvanica, Lycium barbarum, Mahonia aquifolium, Physocarpus opulifolius, Pinus strobus, Populus × canadensis, Prunus serotina, Quercus rubra, Rhus typhina, Robinia pseudoacacia, Symphoricarpos albus, Syringa vulgaris. Dominant characteristics of expansive and invasive species are dispersibility of seeds and capacity of vegetative propagation.

Tradicionalna upotreba samoniklog jestivog bilja na području općine Kršan (Istra, Hrvatska)

U ovom radu prikazani su rezultati etnobotaničkog istraživanja tradicionalnog korištenja samoniklog jestivog bilja na području općine Kršan, provedenog tijekom 2017. i 2018. godine. Ukupno je dokumentirano 107 biljnih vrsta (od toga 17 kultiviranih vrsta), u prosjeku 26 vrsta po jednom intervjuu. Rezultati ovog istraživanja pokazuju da se najveći broj samoniklih biljaka najčešće koristi kao: sirove salate ili kuhano povrće (37 vrsta), sirovo divlje voće (24 vrste), svakodnevni / ili medicinski čajevi (18 vrsti), začinske biljke (4 vrste), a 7 vrsta ima specifičnu medicinsku uporabu. Pored najčešće spominjane vrste povrća, popularne šparoge (Asparagus acutifolius L.), zanimljiva je i vrlo česta konzumacija šparogama sličnih biljaka čiji se mladi izdanci jedu sirovi, kuhani ili u mješavini s kokošjim jajima: Ruscus aculeatus L., Clematis vitalba L., Tamus communis L. i Humulus lupulus L. Zabilježena je i hrana korištena u vrijeme velike gladi (za vrijeme 1. i 2. svjetskog rata), primjerice Quercus ilex L. Posebna karakteristika lokalne gastronomije je kiseljenje mladih izbojaka Ruscus aculeatus L., kao i kiseljenje Portulaca oleraceae L. koje koriste kao salatu / prilog mesnim jelima tijekom zime. Uz spomenute vrste najčešće korišteno povrće je: Foeniculum vulgare L., Urtica dioica L., Taraxacum officinale L., Cichorium inthybus L. i Sonchus oleraceus L. Najčešće korišteno divlje voće je: Rubus ulmifolius L., Juniperus oxycedrus L., Cornus mas L., Morus nigra L., M. alba L. i Sorbus domestica L. Upotreba nekultiviranog povrća duž Mediteranskog dijela Hrvatske još je uvijek relativno česta, iako je u opadanju, kao i u cijeloj Europi i na globalnoj razini.