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Abstract: The increasing use of biodegradable plastics (BPs) as alternatives to conventional plastics (CPs) is leading to the accumulation of biodegradable microplastics (BMPs) in terrestrial environments. Contrary to assumptions of rapid degradation, BMPs can persist in soil long enough to interact with key biological processes. This review advances the field by proposing a mechanistic framework linking BMP aging and degradation, soil physicochemical transformations, plastisphere assembly, rhizosphere interactions, and plant responses, and by critically evaluating the sources of inconsistency across studies. We show that divergent effects of BMPs can be best explained by four interacting determinants: polymer chemistry and additive composition, aging-driven surface transformations, soil physicochemical properties, and rhizosphere processes including plant-mediated effects. Through these coupled pathways, BMPs can alter aggregation, pore architecture, pH, enzyme activity, and carbon and nutrient cycling, thereby reshaping the soil environment in which microorganisms and roots interact. BMP surfaces can also act as dynamic microbial niches that promote biofilm formation, shift microbial community composition and function, and under certain conditions may facilitate pollutant transport, pathogen persistence, and horizontal gene transfer. Plant responses to BMPs are predominantly indirect and emerge from rhizosphere-mediated processes, which helps explain the wide variability in reported plant responses, ranging from subtle metabolic changes to pronounced growth inhibition. However, current evidence is constrained by short-term studies and insufficient consideration of aged materials. Biodegradability should therefore not be equated with low ecological risk in soils. Progress in this field requires integrative approaches linking BMP properties, plastisphere dynamics, and plant–soil interactions over time.
Keywords: soil ecosystem, biodegradable microplastics, plant microbiome, plastisphere, rhizosphere, nutrient cycling
Published in DiRROS: 06.05.2026; Views: 169; Downloads: 121
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Abstract: Abscission is a tightly regulated process in which plants shed unnecessary, infected, damaged, or aging organs, as well as ripe fruits, through predetermined abscission zones in response to developmental, hormonal, and environmental signals. Despite its importance, the underlying mechanisms remain incompletely understood. This study highlights the deleterious effects of abscission on chloroplast ultrastructure in the cells of the tomato flower pedicel abscission zone, revealing spatiotemporal differential gene expression and key transcriptional networks involved in chloroplast vesiculation during abscission. Significant changes in chloroplast structure and vesicle formation were observed 8 and 14 h after abscission induction, coinciding with the differential expression of vesiculation-related genes, particularly with upregulation of Senescence-Associated Gene 12 (SAG12) and Chloroplast Vesiculation (CV). This suggests a possible vesicle transport of chloroplast degrading material for recycling by autophagy-independent senescence-associated vacuoles (SAVs) and CV-containing vesicles (CCVs). Ethylene signaling appears to be involved in the regulation of these processes, as treatment with a competitive inhibitor of ethylene action, 1-methylcyclopropene, delayed vesiculation, reduced the expression of SAG12, and increased expression of Curvature Thylakoid 1A (CURT1A). In addition, chloroplast vesiculation during abscission was associated with differential expression of photosynthesis-related genes, particularly those involved in light reactions, underscoring the possible functional impact of the observed structural changes. This work provides new insights into the molecular and ultrastructural mechanisms underlying abscission and offers potential new targets for agricultural or biotechnological applications.
Keywords: abscission, chloroplast vesiculation, CURT1A, CV-containing vesicle, senescence-associated vacuole, ethylene, gene expression, tomato flower pedicel
Published in DiRROS: 10.01.2025; Views: 1312; Downloads: 829
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Abstract: »Iz take smo snovi kot sanje« je rekel Shakespeare. Jaz pa pravim: »Iz take smo snovi kot znanje... Spoznanje je misel, ki jo ujamemo v letu, jo umestimo v svoje pasti in udejanimo v svojem znanstvenem poskusu. Potem okameni in postane stvarnost. Znanje postavimo v nek kontekst. Kamenček v mozaiku, kamor morda sploh ne sodi, a vendarle se prej ali slej umesti, kamor res sodi.« Ali pa ne! Kam bo sodila naša misel jutri, ko bo fluidni mozaik našega spoznanja o vsem kar nas obdaja in kar počnemo, dobil spet drugo podobo – ne vemo ..! Ali nam bo dano kdaj spoznati predvsem človeka samega, spletne mreže naših nevronov? Ali nam bo dano to spoznanje ali ne, je težko reči, saj je eno človeško življenje za to prekratko. Rodimo se in umremo v ne-vedenju. Tako sama vidim svoje delo. Tako raziskovalci tu gledamo živa bitja in naravo – biologijo. Mnogo bolje bo danes o tem govoril naš znanstveno - umetniški film, zato bodi dovolj..! Ker dan zahteva od nas še mnogo več – treba je preliti to znanje med ljudi. Treba ga je dajati mladim raziskovalcem. So kot nežni cvetovi, žejni jutranje rose učenosti - a so tudi zahtevni, neusmiljeni, brezsramni in izčrpavajoči. A prav vzgoja mladih raziskovalcev, ki jih pri nas opremimo še z dodatnimi znanji in veščinami tako, da bodo kos vsem izzivom družbe in gospodarstva, je pomembno poslanstvo NIBa. Ti novi doktorji znanosti, ki izhajajo iz našega dela, bodo namreč nujno potrebna gonilna sila inovativnega razvoja Slovenije. A sedanjost zahteva tudi, da pretopimo znanje v zlato. Žal nismo alkimisti in vmes – med znanjem in bogastvom je še mnogo, na kar ne moremo vplivati. Je kopica drugih elementov in podpornih sistemov, za katere znanost in znanstveniki sami ne moremo dosti narediti. Lahko le pomagamo graditi ta podporni sistem do mere, ko bo zlitje z njim rodilo resnično konkurenčnost in uspeh. A to se ne doseže čez noč... Ko se obračam v zgodovino, ugotavljam, da smo bili včasih že kar na pravi poti. Da smo se znali odrekati in videti višje cilje. Znanost je že lepo shodila in rastoča industrija 70-80 let ji je znala podajat roko. A to so bili drugačni časi in kaj se je zgodilo potem – je preveč za današnji slavnostni dan! Nekako v tistem času se je rodil NIB. Vizionarski pogled prof. Miroslava Zeia, pobudnika ustanovitve našega instituta, se je danes uresničil. NIB torej ni rodila politika za razliko od večine, posebno naravoslovno tehničnih inštitutov, ki so imeli zato tudi potrebno državno podporo. NIB je rasel kot samorastnik, samosvoje, kar nas je utrdilo za preživetje, tudi za prihajajoče obdobje. Tako ga danes zaradi odličnega znanstvenega dela in kompetentnih raziskovalcev nova tehnološka predvidevanja vključujejo kot močnega partnerja v svojem razvoju. Posebno v zadnjem desetletju zaznamo prodor, tako v znanstvenem delu z naraščajočimi dobrimi publikacijami (npr. v prestižni reviji Nature) kot tudi na razvojnem področju. V 70 letih se je inštitutu priključila Mor - ska biološka postaja (MBP), ki je ime - la pomemben vpliv tudi na delo na - ših drugih področij, kot so bile tedaj rastlinska fiziologija, entomologija in predvsem raziskave ekosistemov. MBP je namreč že takrat izvajala svo - je družbeno pomembno poslanstvo v strateškem delovanju na področju razvoja in raziskav širšega obalnega okolja in upravljanja z morskimi viri. Podobno smo danes tudi na skoraj vseh področjih svojega dela in eksper - tize stalni partner ministrskih služb in agencij, prvenstveno na področju oko - lja, kmetijstva in zdravstva. Postali in ostali smo - na eni strani nepogrešljivi izvajalec in na drugi svetovalec politi - ke pri načrtovanju njenega razvoja, ne nazadnje tudi na več segmentih nujne sinhronizacije z Evropsko politiko in direktivami. V zadnjem desetletju smo uspeli ob pod - pori resornega ministrstva za znanost, visoko šolstvo in tehnologijo posodo - biti infrastrukturo MBP, tako da je ta danes ena najmodernejših ustanov na severnem Jadranu in okolici. Upamo, da bomo to lahko storili tudi v Lju - bljani na Biološkem središču, saj že po petnajstih letih po vselitvi to poka po šivih, predvsem zaradi prodora mla - dih ljudi, ki prihajajo na NIB, vse več tudi iz tujine. Biologija je danes namreč v svetu ena najbolj hitro se razvijajočih disciplin in prodira v mnoge pore novih teh - nologij – od klasičnih vrst biotehno - logije do nano-tehnologij in celo do vesoljskih tehnologij – česar se prav doma premalo zavedamo! Sodelovati s poslovnim sektorjem poskušamo, bodisi preko vključevanja v nove Cen - tre odličnosti, Centre kompetentnosti ter preko možnih povezovanj s pod - jetji doma in tudi preko naših meja, poskušamo… A po mojem osebnem prepričanju je najbolj učinkovito usta - navljanje lastnih podjetij, strategija, ki je prav ob 50 letnici rodila naše prvo odcepljeno podjetje Biosistemika, ki je zrasla iz naših raziskav s področja sistemske biologije. Predmet naših raziskav je torej zelo ra - znolik - od bakterij do človeka in njegovega okolja. Rdeča nit je seveda ohranjene zdravega okolja za zdrave - ga človeka, kar je nedvomno najvišja kakovost življenja. Naj tu končam. Vabim vas torej v prije - ten popoldan, ko boste občutili biolo - gijo in se s tem zavedli sebe kot živega bitja, ki je le del narave in nič več, a nič manj kot to.
Published in DiRROS: 04.09.2024; Views: 1217; Downloads: 739
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Abstract: The important economic sector of world grapevine production of 74 million tons is threatened by several grapevine yellows diseases associated with the presence of phytoplasmas. There is a lack of availability of well-characterized and certified material suitable for use as reference positive controls in different diagnostic schemes, validation studies, performance studies and proficiency tests, which are all part of the management programs for fast and accurate detection of grapevine yellows phytoplasmas.
Keywords: reference material, detection, plant pathogen, digital droplet PCR
Published in DiRROS: 03.09.2024; Views: 1470; Downloads: 775
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Abstract: Abscission occurs specifically in the abscission zone (AZ) tissue as a natural stage of plant development. Previously, we observed delay of tomato (Solanum lycopersicum) leaf abscission when the LX ribonuclease (LX) was inhibited. The known association between LX expression and programmed cell death (PCD) suggested involvement of PCD in abscission. In this study, hallmarks of PCD were identified in the tomato leaf and flower AZs during the late stage of abscission. These included loss of cell viability, altered nuclear morphology, DNA fragmentation, elevated levels of reactive oxygen species and enzymatic activities, and expression of PCD-associated genes. Overexpression of antiapoptotic proteins resulted in retarded abscission, indicating PCD requirement. PCD, LX, and nuclease gene expression were visualized primarily in the AZ distal tissue, demonstrating an asymmetry between the two AZ sides. Asymmetric expression was observed for genes associated with cell wall hydrolysis, leading to AZ, or associated with ethylene biosynthesis, which induces abscission. These results suggest that different abscission-related processes occur asymmetrically between the AZ proximal and distal sides. Taken together, our findings identify PCD as a key mechanism that occurs asymmetrically during normal progression of abscission and suggest an important role for LX in this PCD process.
Keywords: plant cell, cell death, abscission
Published in DiRROS: 05.08.2024; Views: 1253; Downloads: 880
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