This study analyzed physiological and molecular characteristics associated with the resistance to aging or anti-senescence in Camellia oleifera Abel. Trees over 100 years old (ancient trees) were compared with those about 30 years old (mature trees). Total chlorophylls, chlorophyll a/b ratio, and hydrogen peroxide concentrations in ancient tree leaves were significantly higher than in their counterparts. Significantly higher activities of superoxide dismutase, peroxidase, and catalase were detected in ancient tree leaves. Nine Chl a/b-binding protein genes, 15 antioxidant enzyme genes, 21 hormone-related genes, and 301 stress-related genes were upregulated, and 42 protein-degradation genes were downregulated in ancient tree leaves. By increasing chlorophyll content and antioxidant enzyme activities and regulating the ageing-related genes expression, ancient C. oleifera leaves maintained remarkable vitality. Although further research is needed, our study may shed some light on how ancient C. oleifera trees can resist ageing and sustain their healthy growth.

• Klíčová slova
• Camellia oleifera, anti-ageing, anti-senescence, plant senescence,
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Below-ground bud banks have experienced much recent interest due to discoveries that they (1) account for the majority of seasonal population renewal in many communities, (2) are crucial to regeneration following disturbance, and (3) have important consequences for plant population dynamics and plant and ecosystem function across a number of habitats. SCOPE: This review presents an overview of the role of bud banks in plant population renewal, examines bud bank life history, summarizes bud bank traits and their potential ecological implications, synthesizes the response of bud banks to disturbance, and highlights gaps to guide future research. The characteristics and life history of buds, including their natality, dormancy, protection and longevity, provide a useful framework for advancing our understanding of bud banks. The fate of buds depends on their age, size, type, location, and biotic and abiotic factors that collectively regulate bud bank dynamics. A bud bank can provide a demographic storage effect stabilizing population dynamics, and also confer resistance to disturbance and invasion. Regeneration capacity following disturbance is determined by interactions among the rates of bud natality, depletion and dormancy (meristem limitation), and the resources available to support the regeneration process. The resulting response of plants and their bud banks to disturbances such as fire, herbivory and anthropogenic sources determines the community's regenerative capacity. CONCLUSIONS: Vegetation responses to environmental change may be mediated through changes in bud bank dynamics and phenology. Environmental change that depletes the bud bank or prohibits its formation likely results in a loss of vegetation resilience and plant species diversity. Standardization of bud sampling, examination of bud banks in more ecosystems and their response to environmental variation and disturbance regimes, employment of stage-structured bud bank modelling and evaluation of the cost of bud bank construction and maintenance will benefit this expanding field of research.

• Klíčová slova
• Bud, below-ground organs, bud bank, clonal, disturbance, meristem, plant traits, population dynamics,
• MeSH
• býložravci MeSH
• ekologie MeSH
• ekosystém * MeSH
• požáry * MeSH
• rostliny MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

BACKGROUND AND AIMS: Senescence is the process of losing fitness when growing old, and is shaped by the trade-off between maintenance and reproduction that makes reproduction more unsure and maintenance more costly with age. In repeatedly reproducing plants, reductions in growth and fertility are signs of senescence. Disturbance, however, provides an opportunity to reset the ageing clock and consequently potentially ameliorate senescence. METHODS: To test the effects of disturbance on traits closely related to fitness and thus to senescence, a long-term garden experiment was established with two short-lived perennial congeners,Barbarea vulgaris and Barbarea stricta, that differ in their ability to resprout after injury. In the experiment, five damage treatments were applied to plants in four different phenophases. KEY RESULTS: It was found that damage to the plant body significantly prolonged life span in B. vulgaris but decreased whole-life seed production in both species. High concentration of seed production in one growing season characterized short life spans. Both more severe damage and a more advanced phenological phase at the time of damage caused reproduction to be spread over more than one growing season and equalized per-season seed production. In terms of seed quality, average weight of a single seed decreased and seed germination rate increased with age regardless of damage. CONCLUSIONS: Although disturbance is able to reset the ageing clock of plants, it is so harmful to plant fitness that resprouting serves, at best, only to alleviate slightly the signs of senescence. Thus, in terms of whole-life seed production, injured plants were not more successful than uninjured ones in the two studied species. Indeed, in these species, injury only slightly postponed or decelerated senescence and did not cause effective rejuvenation.

• Klíčová slova
• Ageing clock, Barbarea stricta, Barbarea vulgaris, disturbance, fitness, injury, life span, phenophase, seed germination, seed number, seed weight,
• MeSH
• Barbarea růst a vývoj   MeSH
• biologické modely MeSH
• časové faktory MeSH
• druhová specificita MeSH
• klíčení * MeSH
• kořeny rostlin růst a vývoj   MeSH
• rozmnožování MeSH
• semena rostlinná růst a vývoj   MeSH
• statistické modely MeSH
• velikost těla MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH