3 years ago

Spatiotemporal heterogeneity of photosystem II function during acclimation to zinc exposure and mineral nutrition changes in the hyperaccumulator Noccaea caerulescens

Michael Moustakas, Gülriz Bayçu, Nurbir Gevrek, Julietta Moustaka, István Csatári, Sven Erik Rognes


We investigated changes in mineral nutrient uptake and translocation and photosystem II (PSII) functionality, in the hyperaccumulator Noccaea caerulescens after exposure to 800 μM Zn in hydroponic culture. Exposure to Zn inhibited the uptake of K, Mn, Cu, Ca, and Mg, while the uptake of Fe and Zn enhanced. Yet, Ca and Mg aboveground tissue concentrations remain unchanged while Cu increased significantly. In the present study, we provide new data on the mechanism of N. caerulescens acclimation to Zn exposure by elucidating the process of photosynthetic acclimation. A spatial heterogeneity in PSII functionality in N. caerulescens leaves exposed to Zn for 3 days was detected, while a threshold time of 4 days was needed for the activation of Zn detoxification mechanism(s) to decrease Zn toxicity and for the stomatal closure to decrease Zn supply at the severely affected leaf area. After 10-day exposure to Zn, the allocation of absorbed light energy in PSII under low light did not differ compared to control ones, while under high light, the quantum yield of non-regulated energy loss in PSII (ΦNO) was lower than the control, due to an efficient photoprotective mechanism. The chlorophyll fluorescence images of non-photochemical quenching (NPQ) and photochemical quenching (qp) clearly showed spatial and temporal heterogeneity in N. caerulescens exposure to Zn and provided further information on the particular leaf area that was most sensitive to heavy metal stress. We propose the use of chlorophyll fluorescence imaging, and in particular the redox state of the plastoquinone (PQ) pool that was found to display the highest spatiotemporal heterogeneity, as a sensitive bio-indicator to measure the environmental pressure by heavy metals on plants.

Publisher URL: https://link.springer.com/article/10.1007/s11356-019-04126-0

DOI: 10.1007/s11356-019-04126-0

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.