Biology subjects

Centritto, M.

Publications and source records attributed to Centritto, M..

2 recordsLinked to original sources

bioRxiv2018

Seedling leaves allocate lower fractions of nitrogen to photosynthetic apparatus in nitrogen fixing trees (Dalbergia odorifera and Erythrophleum fordii) than in non-nitrogen fixing trees (Betula alnoides and Castanopsis hystrix) in subtropical China

Photosynthetic-nitrogen use efficiency (PNUE) is a useful trait to characterize leaf economics, physiology, and strategy. In this study, we investigated the differences in PNUE, leaf nitrogen (N) allocation, and mesophyll conductance (gm) in Dalbergia odorifera and Erythrophleum fordii (N-fixing trees), and Betula alnoides and Castanopsis hystrix (non-N-fixing trees). Seedlings of the four species were cultured in pots and received the same nutrient solution, water volume, and light. LiCor-6400 was used to determine fluorescence yield, photosynthetic response to light, and intercellular CO2 concentration (Ci). N allocation fractions in the photosynthetic apparatus were calculated according to Niinemets and Tenhunen method; gm was calculated according to variable J, EDO, and A-Ci curve fitting methods. PNUE of D. odorifera and E. fordii were significantly lower than those of B. alnoides and C. hystrix because of their allocation of a lower fraction of leaf N to Rubisco (PR) and bioenergetics (PB). Mesophyll conductance had a significant positive correlation with PNUE in D. odorifera, E. fordii, and B. alnoides. The fraction of leaf N to cell wall (PCW) had a significant negative correlation with PR in B. alnoides and C. hystrix. We conclude that B. alnoides and C. hystrix optimized their leaf N allocation toward photosynthesis, with the trade-off being N allocation to the cell wall and Rubisco. Thus, these two species may have a higher competitive ability in natural ecosystems with fertile soil.

ecology↗

bioRxiv2018

Impact of high phosphorous and sodium on productivity and stress tolerance of Arundo donax plants

Arundo donax L. is an invasive species recently employed for biomass production that emits large amounts of isoprene, a volatile compound having important defensive role. Here, the potential of A. donax to grow in degraded soils, characterized by poor fertility, eutrophication and/or salinization, has been evaluated at morphological, biochemical and transcriptional level. Our results highlight sensitivity of A. donax to P deficiency. Moreover, we show that A. donax response to salt stress (high sodium, Na+), which impaired plant performance causing detrimental effects on leaf cells ultrastructure, is characterized by enhanced biosynthesis of antioxidant carotenoids and sucrose. Differently from Na+, high phosphorous (P) supply did not hamper photosynthesis although it affected carbon metabolism through reduction of starch content and by lowering isoprene emission. In particular, we revealed on salt-stress leaves that high P enhanced the expression of genes involved in abiotic stress tolerance, but further increased diffusive limitations to photosynthesis and slowed-down sugar turnover without modifying isoprene emission. Therefore, despite limiting productivity, high P improved A. donax tolerance to salinity by favouring the accumulation of carbohydrates that protect cells and increase osmotic potential, and by stimulating the synthesis of antioxidants that improves photo-protection and avoids excessive accumulation of reactive oxygen species.\n\nHighlightsArundo donax is sensitive to elevated salinity. High phosphorous supply to salt-stressed A. donax enhances transcriptomic changesthat induce the onset of physiological mechanisms of stress tolerance but limits productivity.

physiology↗