Physiological and molecular aspects of sugar beet tolerance to drought

Istraživanja su sprovedena na jedanaest genotipova šećerne repe (Beta vulgaris ssp. vulgaris, L., označeni brojevima 1-11) koji su u poljskim uslovima ispoljili razlike u opservacionom testu nivoa tolerantnosti prema suši (visoko, srednje i nisko tolerantni). U prvom delu eksperimenta biljke su gajene u polukontrolisanim uslovima, u stakleniku u supstratu koji je bio mešavina zemlje i peska. Biljke su svakodnevno zalivane tokom 90 dana, nakon čega je izazvan vodni deficit prestankom zalivanja, dok je kod kontrolnih biljaka zalivanje nastavljeno. Pet dana po prestanku zalivanja analizirani su parametri koji bi trebalo da ukažu na genotipske razlike u smislu tolerantnosti prema nedostatku vode. Utvrđen je sadržaj vode/suve materije u zemljištu i u biljnim tkivima (koren stablo i list). Lisna površina i koncentracija pigmenata hloroplasta su ustanovljeni kod kontrolnih biljaka s ciljem utvrđivanja genotipskih specifičnosti. Osim toga, mereni su parametri fluorescencije hlorofila (F0, Fm, Fv, Fv/Fm i t1/2) kako bi se utvrdio efekat stresa izazvanog nedostatkom vode na inhibiciju transporta elektrona kroz PSII, i koncentracija slobodnog prolina, amino kiseline koja se nakuplja u uslovima stresa. U drugom delu eksperimenta ovi genotipovi su testirani u kontrolisanim, in vitro uslovima gajenja. Aksilarni izdanci su gajeni na podlozi za mikropropagaciju sa 0 (kontrola), 3 i 5% polietilen glikola (PEG 6000) pune četiri nedelje, a potom su vršene analize. Utvrđena je sveža masa izdanaka, sadržaj suve materije i koncentracija slobodnog prolina. U trećem delu eksperimenta upoređene su razlike u ekspresiji 13 kandidat-gena, koji su povezani sa reakcijom biljaka na uslove stresa, posebno suše, u listovima biljaka gajenih u polukontrolisanim uslovima. Biljke izložene stresu u polukontrolisanim uslovima gajenja su u proseku imale oko tri lista manje, za četiri procenta veći udeo suve materije i sedmostruko veći sadržaj prolina. Koncentracija prolina u listovima je bila viša u uslovima nedostatka vode u polukontrolisanim uslovima kod svih genotipova, a posebno kod nekih iz slabo tolerantne (2, 6) i visoko tolerantne (4) grupe. U in vitro uslovima usled tretmanom PEG-om smanjila se ukupna suva masa i više nego prepolovio broj aksilarnih izdanaka. PEG u koncentraciji od 3% je doveo do povećanja ukupne sveže mase, a koncentracija prolina se povećala se porastom koncentracije PEG. Koncentracija prolina u uslovima stresa je kod oba eksperimenta bila značajno povećana u odnosu na kontrolu i to u in vitro uslovima šest puta, a u polukontrolisanim uslovima u stakleniku šesnaest puta u odnosu na odgovarajuće kontrole. Povećanje sadržaja prolina u biljkama gajenim u polukontrolisanim uslovima je bilo tri puta veće u odnosu na eksperiment sa PEG-om. Koncentracija slobodnog prolina, kao jedan od potencijalnih parametara - pokazatelja tolerantnosti genotipova šećerne repe prema suši, je adekvatniji od ukupne suve mase. Rezultati su pokazali da je test u in vitro uslovima (posebno tretman 3% PEG-om) efikasiji za ocenu tolerantnosti prema suši od eksperimenta u polukontrolisanim uslovima. Grupisanje genotipova prema nivou tolerisanja nedostatka vode na osnovu koncentracije prolina ustanovljene u ekperimentu in vitro dalo je isti rezultat kao i opservacioni test u poljskim uslovima. Utvrđene su promene u ekspresiji kandidat-gena u uslovima suše u odnosu na kontrolu, a ustanovljene su i razlike između genotipova. Jedan od analiziranih kandidat-gena može da posluži za dalji razvoj markera. Ovi rezultati mogu da se primene u procesu oplemenjivanja šećerne repe koje je usmereno na povećanje tolerantnosti prema ovom abiotičkom činiocu

Free proline accumulation in young sugar beet plants and in tissue culture explants under water deficiency as tools for assessment of drought tolerance

Proline is the most widely distributed metabolite that accumulates under various stress conditions, including the lack of water. To evaluate the suitability of proline accumulation triggered by drought stress to screen sugar beet genotypes for drought tolerance, we analysed accumulation of free proline in eleven genotypes classed in three levels of relative tolerance (low, medium, high), as assessed visually in field cultivation. Analysis was performed in two tests: 1) in greenhouse, where 90 days old plants were exposed to a short-term water deficiency and 2) in tissue culture where the lack of water was imposed by addition of 3 or 5% (w/v) polyethylene glycol (PEG, MW 6000). Both the in vitro test with increasing levels of PEG and the suspension of water supply in the greenhouse experiment showed large increases of free proline in tissues of sugar beet explants or leaves consequent to water restriction, as well as reduction in fresh weight, tissue water content and axillary bud formation. Stress effects varied considerably among genotypes classed at low, medium and high levels of field tolerance to drought stress, but were similar as class averages, except for proline in vitro, which was significantly higher for genotypes in the high tolerance group, and allowed separating them from those in the less tolerant groups. Proline response in the in vitro test correlated better than the response in greenhouse experiment with the field assessed drought tolerance of genotypes

Sugar Beet Tolerance to Drought: Physiological and Molecular Aspects

Drought often reduces sugar beet yield in the Balkan agroecological region. Climate forecasts indicate that this negative trend of drought periods will continue. Tolerance to drought is a complex trait, which comprises involvement of both physiological and molecular mechanisms in plants. This research was conducted on 11 sugar beet genotypes, which showed different tolerance to drought in the field. Experiment had three parts: water deficiency caused by cessation of watering conducted in the greenhouse, water deficiency imposed by different concentrations of polyethylene glycol on plants grown in tissue culture, and analysis of alterations in gene expression under drought. Plants exposed to stress in greenhouse had on average three leaves less, 4% lower water content, and seven-fold higher proline content. Classification of genotypes with respect to the level of tolerance to water deficiency on the basis of concentration of free proline, assessed in the experiment in vitro, corresponded to the result of the observation test in the field. Changes in the expression of candidate genes under drought suggest that one of them might be used for further development as a DNA-based marker. These results can be applied in sugar beet breeding aimed at increasing tolerance to water deficiency

Primena statističkih transformacija na izmerene koncentracije prolina u listu šećerne repe u uslovima suše

Eleven sugar beet genotypes were tested for their capacity to tolerate drought. Plants were grown in semi-controlled conditions, in the greenhouse, and watered daily. After 90 days, water deficit was imposed by the cessation of watering, while the control plants continued to be watered up to 80% of FWC. Five days later concentration of free proline in leaves was determined. Analysis was done in three replications. Statistical analysis was performed using STATISTICA 9.0, Minitab 15, and R2.11.1. Differences between genotypes were statistically processed by Duncan test. Because of nonormality of the data distribution and heterogeneity of variances in different groups, two types of transformations of row data were applied. For this type of data more appropriate in eliminating nonormality was Johnson transformation, as opposed to Box-Cox. Based on the both transformations it may be concluded that in all genotypes except for 10, concentration of free proline differs significantly between treatment (drought) and the control.Analizirana je tolerantnost 11 genotipova šećerne repe prema nedostatku vode. Biljke su gajene u polukontrolisanim uslovima, u stakleniku, na supstratu koji je bio mešavina zemlje i peska, pri čemu su biljke svakodnevno zalivane. Posle 90 dana, vodni deficit je izazvan prestankom zalivanja, dok su biljke kontrolne grupe i dalje zalivane, do 80% PVK. Pet dana kasnije utvrđena je, u tri ponavljanja, koncentracija slobodnog prolina u listovima. Statistička analiza je izvršena korišćenjem programa Statistica 9.0, Minitab 15 i R2.11.1. Zbog velike varijabilnosti podataka i odstupanja od normalne raspodele analiziran je uticaj različitih transformacija eksperimentalnih podataka na konačan zaključak. Razlike između aritmetičkih sredina poređene su primenom Dankanovog testa. Na osnovu obe primenjene transformacije može se zaključiti da se kod svih genotipova, izuzev genotipa 10, koncentracija slobodnog prolina u listovima značajno razlikuje između biljaka izloženih suši i kontrole

Elementi retkih zemalja - itrijum i više biljke

Rare earth elements (REEs) form a chemically uniform group with very similar physical and chemical properties. The REEs include the elements scandium, yttrium, and the lanthanides from lanthanum to lutetium. They are widely distributed and present in all parts of the biosphere. REEs are required in industry, agriculture, medicine, biotechnology, environmental problems and many other fields. Lately, many experiments show their positive or negative, first of all nonspecific, effect on life processes of higher plants as well as growth and yield of cultivated species, but the physiological mechanisms are still not well understood. It has been determined that yttrium is widely distributed in plants, as well as that certain plant species uptake yttrium at different extent. Its highest accumulation is in the root and the leaf. Although yttrium was discovered more than two centuries ago, its effect on higher plants - their anatomical and morphological built, physiological and biochemical processes etc. - is very little known. One of the basic reasons is that yttrium, as well as other REEs elements, according to current knowledge, is not biogenic for higher plants and - wider - for live organisms. The objective of this paper is to concisely show previous knowledge about yttrium in the plant world.Elementi retkih zemalja (REEs) su iz hemijski uniformnih grupa sa veoma sličnim fizičkim i hemijskim osobinama. REEs uključuju elemente kao što su: skandijum, itrijum i lantanide od lantana do lutecijuma. Oni su široko rasprostranjeni i prisutni u svim delovima biosfere. REEs se koriste u industriji, poljoprivredi, medicini, biotehnologiji, kod problema zaštite životne sredine i u mnogim drugim poljima. U novije vreme, u mnogobrojnim ogledima je utvrđeno njihovo pozitivno ili negativno, pre svega nespecifično, dejstvo na životne procese viših biljaka kao i na rastenje i prinos gajenih vrsta, ali fiziološki mehanizmi dejstva još uvek nisu razjašnjeni. Utvrđeno je da je itrijum široko rasprostranjen u biljnom svetu, kao i da pojedine biljne vrste itrijum u različitoj meri usvajaju. Najveće je njegovo nakupljanje u korenu i listovima. Iako je itrijum otkriven pre više od dva veka, o njegovom dejstvu na više biljke, na njihovu anatomsku i morfološku građu, fiziološke i biohemijske procese i dr. veoma malo je poznato. Jedan od osnovnih razloga za to je da itrijum, kao i ostali elementi REEs prema dosadašnjim saznanjima nisu biogeni za više biljke i šire za žive organizme. Cilj ovog pregleda je da u sažetom obliku prikaže dosadašnja saznanja u vezi sa itrijumom u biljnom svetu

Rare earth elements and plants

There has been a growing interest in the study of the rare earth elements (REEs) in recent decades of the last century, with the exploitation of REEs resources and applications in modern industry, medicine, agriculture and biotechnology. The main application of REEs is as new materials for recent technologies in the modern industry and agriculture, where low concentrations of REEs-based fertilizers are used to increase yield and quality of crops. Positive, negative or nil effects of RREs on plant growth, chemical composition and yield were observed in experiments done in many countries, but the physiological and biochemical mechanisms are still not well understood. Essentiality of REEs for living organisms or their threat to the environment has not been identified so far

Akumulacija suve materije ozime pšenice i ječma u različitim rokovima setve

Dry matter accumulation is one of the best estimates for crop reaction to the effect of genotype or environmental factors. However, there is a lack of information about comparative crop growth between wheat and barley under conditions of the Pannonian climate. The objectives of this work were to study and compare the patterns of biomass accumulation in wheat and barley, and identify the role of the logistic curve parameters in the determination of the final biomass. Therefore, field trials with two two-row winter barley and two winter wheat cultivars were carried out in two successive growing seasons with four sowing dates. Results from our study showed that grain yield and crop biomass were under significant influence of cultivar and sowing date in both growing seasons. The highest grain yield and crop biomass at maturity were obtained with early sowing - first and second sowing date. There was a significant positive relationship between the crop biomass and grain yield in both species. Barley and wheat had similar strategies for biomass determination. Crop biomass at maturity was positively associated with the duration of growing phases, while the relationship with weighted mean absolute growth rate was negative. Early sowing enables prolongation in duration of different phases of crop biomass accumulation, leading to significant biomass and grain yield increase.Akumulacija suve materije je jedan od najboljih pokazatelja reakcije useva na uticaj genotipa i faktora sredine. Međutim, nedostaju uporedni podaci o rastu pšenice i ječma u uslovima Panonske nizije. Cilj ovog istraživanja je bilo ispitivanje i poređenje akumulacije suve materije pšenice i ječma i utvrđivanja značaja parametara logističke krive u formiranju ukupne biomase. Ogled sa dve sorte dvoredog ozimog ječma i dve sorte ozime pšenice je sejan dve sezone u četiri roka setve. Rezultati ovog ispitivanja ukazuju da je prinos zrna i suve materije bio pod značajnim uticajem roka setve i genotipa u obe sezone. Setva u prvom i drugom roku dala je najveći prinos zrna i biomase. Utvrđena je pozitvna veza između biomase useva i prinosa zrna kod obe vrste. Pšenica i ječam su imali slične tendencije u nakupljanju suve materije. Biomasa u zrelosti je bila u pozitivnoj vezi sa dužinom vegetacionog perioda, a u negativnoj vezi sa procenjenom srednjom apsolutnom brzinom rasta. Rana setva omogućava produženje trajanja različitih faza akumulacije suve materije, dovodeći do značajnog povećanja prinosa i suve materije kod ječma i pšenice

Uticaj kadmijuma na klijanje semena i rast pšenice

In this study, the effect of Cd on the germination, growth of seedlings and composition of plants deriving from contaminated grains, grown in the field, was examined. Wheat grains were soaked in Cd-containing solutions: 0 (control, deionized water), 10-5 , 10-4 , 10-3 , and 10-2 M CdCl 2 during 24h. One portion of grains was used to test germination and seedling growth, while the other was sown in the field. The concentration of Cd in the grains almost linearly increased with the increase in the applied concentrations of Cd, which reduced the germination and energy of germination and increased the proportion of atypical seedlings. Larger concentrations of Cd significantly impaired the growth of seedlings (length of the shoots and roots, dry matter mass). In the grains of the field-grown plants the concentrations of N, P, and K were not affected by Cd, but their concentrations in the straw declined (especially of N). These results suggest that the emergence and development of plants on the soil polluted by Cd are likely to be significantly limited and yield reduced.Kadmijum (Cd) je potencijalni zagađivač sredine živih organizama i pri većim koncentracijama odlikuje se jakim fitotoksičnim dejstvom. U radu je u laboratorijskim uslovima proučeno dejstvo različitih koncentracija kadmijuma na klijanje i rast mladih biljaka pšenice, a u poljskim uslovima njegov uticaj na koncentraciju mineralnih materija u zrnu i slami u fazi pune zrelosti biljaka, koje su potekle od zrna tretiranog kadmijumom. S povećanjem koncentracije kadmijuma u fazi bubrenja semena skoro se linerano povećala njegova koncentracija u semenu. Utvrđeno je da veće koncentracije kadmijuma značajno smanjuje klijanje i energiju klijanja semena, a povećavaju učešće atipičnih klijanaca i neproklijalog semena. Veće koncentracije kadmijuma značajno su smanjile rast mladih biljaka kao i masu njihove suve materije. Rast nadzemnog dela i korena smanjen je u većoj meri od mase suve materije, na osnovu čega se može zaključiti da je kadmijum u većoj meri uticao na faktore rasta nego na stvaranje suve mase. Najveća primenjena koncentracija kadmijuma smanjila je hidratisanost 68 nadzemnog dela mladih biljaka. Bubrenje semena u prisustvu različitih koncentracije kadmijuma nije uticalo na koncentraciju azota, fosfora i kalijuma u zrnu, a smanjilo je njihovo prisustvo u slami, naročito azota na kraju vegetacije. Dobijeni rezultati potvrđuju nalaze ranijih istraživanja kod drugih biljnih vrsta na osnovu kojih su fiziološki i biohemijski procesi klijanja semena značajno inhibirani u prisustvu većih koncentracija kadmijuma. Na osnovu navedenog može se predvideti da će na zemljištu zagađenom kadmijumom nicanje useva i rast mladih biljaka pšenice biti ograničeno, što će se nepovoljno odraziti na prinos useva

Koncentracija barijuma u zrnu vrsta aegilops i triticum

The aim of this study was to evaluate the concentration of barium in grain of various Aegilops and Triticum species with different genomes. The studied species differed significantly with respect to the concentration of barium. The grain of wild diploid Aegilops speltoides, the donor of B genome, contained significantly higher Ba concentration than all other analyzed genotypes. Wild and cultivated tetraploid wheats (Triticum diciccoides, Triticum dicoccon, Triticum turgidum and Triticum durum) had the lowest Ba concentration in grain. The modern cultivated hexaploid varieties presented substantial variation in grain concentration of barium. The highest Ba concentration (3.42 mg/kg) occurred in Serbian winter wheat variety Panonnia.Cilj ovog istraživanja bio je da se procene koncentracije barijuma u zrnu različitih genotipova Aegilops i Triticum vrsta. Ispitivane vrste su se značajno razlikovale u odnosu na koncentraciju barijuma. Zrno divljeg diplo ida Aegilops speltoides, donator B genoma sadrži znatno veću koncentraciju barijuma nego svi ostali ispitivani genotipovi. Divlja i pitoma tetraploidna pšenica (Triticum diciccoides, Triticum dicoccon, Triticum turgidum i Triticum durum) imala je najnižu koncentraciju barijuma u zrnu. Moderne gajene heksa plo idne sorte po kazale su značajne varijacije u koncentraciji barijuma u zrnu. Najveće koncentracije (3,42 mg/kg) ustanovljene su kod “Panonije”, ozime sorte pšenice proizvedene u Srbiji

Efekat Ni na koncentraciju najzastupljenijih esencijalnih katjona u nekim vrstama iz roda Brassica

Some plants from the genus Brassica have the ability to tolerate excessive concentrations of heavy metals, including Ni. Considering the fact that Ni is a very toxic element for living beings we wanted to examine its influence on some species from genus Brassicaceae. The aim of this study was to investigate the effect of Ni on distribution and accumulation of essential macronutrients from the standpoint of food quality and phytoremediation potential. Experiments were performed using winter (W) and spring (S) varieties of rapeseed (Brassica napus, L.), white mustard (Brassica alba, L.), black mustard (Brassica nigra, L.) and turnip (Brassica rapa, L.). The seeds were exposed to 10 µM Ni from the beginning of germination. Plants were grown in water cultures, in semi-controlled conditions of a greenhouse, on ½ strength Hoagland solution to which was added Ni in the same concentration as during germination. Concentrations and distribution of Ca, Mg, K in leaf and stem were altered in the presence of increased concentration of Ni. Significant differences were found between the control and Ni-treated plants as well as among the genotypes.Neke biljke iz roda Brassica imaju sposobnost tolerancije prekomerne koncentracije teških metala, uključujući i nikal (Ni). Ispitivanje efikasnosti apsorpcije i akumulacije teških metala interesantno je sa stanovišta: 1) bezbednosti hrane, i 2) potencijala za fitoremedijaciju. Cilj ovog rada je da se ispita efekat nikla na distribuciju i akumulaciju nekih esencijalnih katjona kao što su kalcijum (Ca), magnezijum (Mg) i kalijum (K). Eksperimenti su izvedeni nad ozimom i jarom uljanom repicom (Brassica napus L.), belom slačicom (Brassica alba, L.), crnom slačicom (Brassica nigra L.) i kupusnom uljanom repicom (Brassica rapa L.). Seme je bilo izloženo uticaju 10 µM nikla (Ni) od početka klijanja. Biljke su gajene u vodenim kulturama, u polukontrolisanim uslovima u stakleniku, na ½ Hogland-ovom hranljivom rastvoru, odnosno potpunom hranljivom rastvoru u koji je dodat nikal (Ni) u istoj koncentraciji kao i tokom klijanja. Sadržaj kalcijuma (Ca), magnezijuma (Mg) i kalijuma (K) u listu i stablu izmenjen je u prisustvu povećane koncentracije nikla (Ni). Značajne razlike ustanovljene su kako između kontrole i tretmana, tako i između genotipova. Svi testirani genotipovi ispoljili su značajnu sposobnost akumulacije nikla (Ni), s tim što je Brassica napus jara forma imala najveće razlike u koncentraciji u odnosu na kontrolu (u listu 67,75 puta, a u stablu 92,5)