Numero 175

Cari socie e soci,

felici riprendere i nostri cari appuntamenti dei VIRTUAL CLUB SIBV.

Il seminario si svolgerà il 10 novembre 2022 dalle ore 17:00 alle ore 18:00 e sarà svolto dalla Dott. Sara Natale dell’Università degli Studi di Trieste.

Stem photosynthesis: an ally for trees facing drought?

Sara Natale1, Martina Tomasella1, Alessandro Alboresi2, Nicoletta La Rocca2, Mariano Battistuzzi2, Francesco Petruzzellis1, Sara Gargiulo3, Valentino Casolo3, Tomas Morosinotto2, Andrea Nardini1

Department of Life Sciences, University of Trieste, Trieste, Italy

Department of Biology, University of Padova, Padova, Italy

Department of Agricultural and Environmental Science, Unit of Plant Biology, University of Udine, Udine, Italy

Mail: sara.natale@phd.units.it

Stem photosynthesis can provide an extra carbon gain that might help woody plants to cope with the detrimental effects of drought.We characterized the photosynthetic apparatus of bark and wood chloroplasts in Fraxinus ornus L. (F.o.). Blue light was mainly absorbed by the outer bark, and far-red enriched light reached the xylem and pith. The stem (bark and wood) photosynthetic apparatus was apparently acclimated to the red-enhanced and low-light environment, as shown by higher amounts of LHCII, PSII, more abundant grana, less PSI and stromal thylakoids compared to leaves. We demonstrate that, despite receiving limited light intensity, and also enriched in red wavelengths, stem chloroplasts are fully photosynthetically active.We then verified if inhibition of stem photosynthesis increases plant vulnerability to drought, by covering stems of F.o. saplings with aluminum foil for 30 days. Plants were then subjected to water stress down to leaf water potentials of -3.5 MPa and then re-watered to quantify their recovery capacity. Data revealed that the lack of stem photosynthesis affected the hydraulic response during a drought event, but did not affect the recovery phase.Finally, we conducted a wider screening of quantum yield of PSII (Fv/Fm) at bark and wood level among Angiosperm species with different vulnerabilities to xylem embolism (P50). We show that species more resistant to drought also displayed higher values of bark Fv/Fm, reinforcing the hypothesis of a possible role of stem photosynthesis in drought stress responses.

Puoi partecipare all’evento telematico cliccando su questo link (link inviato via email)

Ciascuna sessione dei Virtual Club sarà svolta attraverso l’uso della Piattaforma Microsoft Teams.

Per ulteriori informazioni non esitate a contattarci inviandoci una e-mail all’indirizzo segretario@sibv.eu

Ci auguriamo ed auspichiamo una grande partecipazione tra i soci ed interazione con gli speaker al fine di rendere questi momenti di incontro virtuale una preziosa occasione per la crescita della nostra comunità,

Un caro saluto

Il Presidente, Laura De Gara                                                                  Il Segretario, Sara Cimini

*******************************************************

Dear SIBV members and associates,

happy to start again with our VIRTUAL CLUB SIBV after the summer break.

The seminar will take place on Nov 10, 2022 from 17:00 to 18:00 and will be held by Dott. Sara Natale of the University of Trieste.

Stem photosynthesis: an ally for trees facing drought?

Sara Natale1, Martina Tomasella1, Alessandro Alboresi2, Nicoletta La Rocca2, Mariano Battistuzzi2, Francesco Petruzzellis1, Sara Gargiulo3, Valentino Casolo3, Tomas Morosinotto2, Andrea Nardini1

Department of Life Sciences, University of Trieste, Trieste, Italy

Department of Biology, University of Padova, Padova, Italy

Department of Agricultural and Environmental Science, Unit of Plant Biology, University of Udine, Udine, Italy

Mail: sara.natale@phd.units.it

Stem photosynthesis can provide an extra carbon gain that might help woody plants to cope with the detrimental effects of drought.We characterized the photosynthetic apparatus of bark and wood chloroplasts in Fraxinus ornus L. (F.o.). Blue light was mainly absorbed by the outer bark, and far-red enriched light reached the xylem and pith. The stem (bark and wood) photosynthetic apparatus was apparently acclimated to the red-enhanced and low-light environment, as shown by higher amounts of LHCII, PSII, more abundant grana, less PSI and stromal thylakoids compared to leaves. We demonstrate that, despite receiving limited light intensity, and also enriched in red wavelengths, stem chloroplasts are fully photosynthetically active.We then verified if inhibition of stem photosynthesis increases plant vulnerability to drought, by covering stems of F.o. saplings with aluminum foil for 30 days. Plants were then subjected to water stress down to leaf water potentials of -3.5 MPa and then re-watered to quantify their recovery capacity. Data revealed that the lack of stem photosynthesis affected the hydraulic response during a drought event, but did not affect the recovery phase.Finally, we conducted a wider screening of quantum yield of PSII (Fv/Fm) at bark and wood level among Angiosperm species with different vulnerabilities to xylem embolism (P50). We show that species more resistant to drought also displayed higher values of bark Fv/Fm, reinforcing the hypothesis of a possible role of stem photosynthesis in drought stress responses.

You can participate in the online event using this link (link sent by email).

Each Virtual Club session will be held via Microsoft Teams.

For more information, do not hesitate to contact us by sending an e-mail to segretario@sibv.eu

We hope for great participation among the members and interaction with the speakers in order to make these moments of virtual meeting a precious opportunity for the growth of our community,

Warm greetings

Il Presidente, Laura De Gara                                                      Il Segretario, Sara Cimini