New publication – Glandular trichomes as a barrier against atmospheric oxidative stress: Relationships with ozone uptake, leaf damage, and emission of LOX products across a diverse set of species

Text from Research in Estonia page (translated from this Novaator article)

Study led by scientists from the Estonian University of Life Sciences indicate that many crops with hairier leaves tolerate ground-level ozone better. The relative content of ground-level ozone in the air has significantly increased since the beginning of the 20th century. It seems that this trend will continue in the future. However, this gas is an environmental poison and harmful to living organisms. Compared to the beginning of the current century, large-scale ozone damage to forest trees as well as on crops has been recorded all over the world.

In a recently-published paper, an international working group, which was led by Estonian plant physiologist from EMÜ, looked at how the gland-tipped hairs of plants protect against the harmful effects of ozone. Plant epidermis has about ten different types of these hairs. Their density also varies between species with some species lacking these hairs altogether. So far, the gland-tipped hairs were primarily associated with a plant’s ability to fight against herbivory.

This time, the scientists limited their focus to agriculturally important plants, such as pumpkins, cucumbers, lavender, rosemary, etc. The research group found that the gland-tipped hairs excrete compounds which have an ozone-neutralising effect. Plants with hairier leaves were significantly more resistant to a high concentration of ozone. Their leaves developed the brown spots marking ozone damage later than less-hairy species.

This paper is significant because, for the first time in history, the  gland-tipped hairs have assumed an important function as neutralisers of ozone.

 

Citation: Li, S., Tosens, T., Harley, P. C., Jiang, Y., Kanagendran, A., Grosberg, M., Jaamets, K. & Niinemets, Ü. (2018). Glandular trichomes as a barrier against atmospheric oxidative stress: relationships with ozone uptake, leaf damage and emission of LOX products across a diverse set of species. Plant, cell & environment, doi.org/10.1111/pce.13128 (link to full text).

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Gravitational life-history effects on male trichomes. So far probably not tested in plants… (pic from here)

Abstract:

There is a spectacular variability in trichome types and densities and trichome metabolites across species, but the functional implications of this variability in protecting from atmospheric oxidative stresses remain poorly understood. The aim of this study was to evaluate the possible protective role of glandular and non‐glandular trichomes against ozone stress. We investigated the interspecific variation in types and density of trichomes and how these traits were associated with elevated ozone impacts on visible leaf damage, net assimilation rate, stomatal conductance, chlorophyll fluorescence, and emissions of lipoxygenase pathway products in 24 species with widely varying trichome characteristics and taxonomy. Both peltate and capitate glandular trichomes played a critical role in reducing leaf ozone uptake, but no impact of non‐glandular trichomes was observed. Across species, the visible ozone damage varied 10.1‐fold, reduction in net assimilation rate 3.3‐fold, and release of lipoxygenase compounds 14.4‐fold, and species with lower glandular trichome density were more sensitive to ozone stress and more vulnerable to ozone damage compared to species with high glandular trichome density. These results demonstrate that leaf surface glandular trichomes constitute a major factor in reducing ozone toxicity and function as a chemical barrier that neutralizes the ozone before it enters the leaf.

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Workgroup and EcolChange seminar – Liisa Kübarsepp about stomata and anatomy of ferns and horsetail

Seminar of Chair of Crop Science and Plant Biology and Centre of Excellence EcolChange, Estonian Univ of Life Sciences .

Liisa Kübrasepp is a junior researcher and a PhD-student in the Estonian University of Life Sciences.

Title of the talk: Stomatal kinetics and anatomy of ferns and horsetails

Time: Monday, 26. March 2018 at 10.15

Place: Tartu, Kreutzwaldi 5 – D-143 (Metsamaja, Aquarium-room)

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The actual evolution of ferns in New Zealand (pic from here)

 

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Congrats to our new PhDs – Shuai and Arooran!

Pics by Arooran Kanagendran and Tiia Kurvits

We had two successful PhD-defences in last couple weeks.

Shuai Li defended his doctoral thesis „Induction of volatile organic compound emissions from leaves upon ozone and methyl jasmonate (MeJa) treatmentson February 26th.

Arooran Kanagendran defended his doctoral thesis „Differential regulation of release of leaf stress volatiles: from terpene synthase gene expression to emission responses under heat, ozone and wounding stresses“. on March 9th.

Here are couple of pictures from these events.

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Arooran presenting

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Watching Arooran´s defence

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Shuai presenting

shuai phd 3

Discussion with the oponent

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Workgroup and EcolChange seminar – Silvano Fares about volatiles in Mediterranean forest systems

Seminar of Chair of Crop Science and Plant Biology and Centre of Excellence EcolChange, Estonian Univ of Life Sciences .

Silvano Fares is senior researcher, Council for Agricultural Research and Economics (CREA), Research Centre for Forestry and Wood, Italy.

Title of the talk: Bi-directional fluxes of ozone and BVOC in Mediterranean forest ecosystems

Time: Wednesday, 26. February 2017 at 10.00

Place: Tartu, Kreutzwaldi 5 – D-143 (Metsamaja, Aquarium-room)

 

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Blog contribution awards 2017

Text by Lauri Laanisto, pic by Tiia Kurvits

Our blog is now about three years old. And once a year, typically during the first seminar of the new year, Ülo gives out little incentives for the ones who have contributed the most to the blog in the preceding year. There is a quaranteed award if you have authored more than five post in the year, plus one award is drawn from the lot of everyone who posted something in the previous year.

Here are the three winners – Lauri Laanisto and Linda-Liisa Veromann-Jürgenson got the “quantity award” and Kaia Kask was the lucky winner of  the drawing -, posing with champagne at 10 am Monday morning…

2018 blogi auhinnad

From left: Kaia, Lauri and Linda-Liisa

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Ülo Niinemets receives the national research award

Text excerpts from Research in Estonia

Last week, the Government of the Republic announced this year’s laureates of the national research awards. ERR Novaator has compiled an overview of what these scientists do.

Award in the field of geology and biology

Academic Ülo Niinemets (born 1970) is a professor with the Institute of Agricultural and Environmental Sciences at the Estonian University of Life Sciences and has been given the award for his cycle of research works, “Integration and adaptation mechanisms of plant photosynthesis: from foliage gradients to global patterns.

All organisms on Earth are dependant on plant photosynthesis – it is the foundation of life. Ülo Niinemets asks: Which structural and physiological properties of plants determine the speed of photosynthesis? By posing this question he is actually asking how global climate change affects the capability of Earth’s vegetation to provide us with clean air and sufficient food. Additionally, he offers insights for developing a new generation of climate models that can predict the production of vegetation and the processes of the biosphere, while also hinting at ways to increase the yield of plants.

Ülo Niinemets has previously been presented with the following awards:

  • 2000 national research award of the Republic of Estonia (together with Olevi Kull) in the field of geology and biology for the work, “Adaptation of photosynthesis in foliage”
  • 2006 national research award of the Republic of Estonia in the field of chemistry and molecular biology for the work, “Physiology of volatile organic compound emissions”
  • 2012 Order of the White Star of the Republic of Estonia, Fourth Class
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Ülo Niinemets (pic from Scanpix)

Ülo was not the only plant physiologist to receive national research award this year. Award for outstanding lifetime achievements in research and development was given to Agu Laisk (born 1938) is a senior research fellow in plant physiology and professor emeritus at the University of Tartu (UT).

Academic Agu Laisk is an outstanding researcher of carbon binding (photosynthesis) in plants, whose research through the years has dealt with the question: What determines the speed of photosynthesis? To answer this, Laisk has led the construction of the world’s fastest photosynthesis measurement system, the preparation of the most complex photosynthesis model and the collection of research results that shed new light upon the photosynthesis process – all of which could be referred to as “first in the world”. Through his work, Laisk has reached one of the highest points atop the world’s scientific pyramid, a height that will remain unreachable to his contemporaries for many years to come.

 

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Upcoming PhD defenses – Shuai Li and Arooran Kanagendran

Text by Lauri Laanisto

We have two upcoming thesis defences.

Firstly, on 26th of February 2018 at 12.15 in Kreutzwaldi 5-2A1 our young researcher, Shuai Li, will defend his doctoral thesis „Induction of volatile organic compound emissions from leaves upon ozone and methyl jasmonate (MeJa) treatments“.

Supervisor: Ülo Niinemets

Opponent: Dr. Silvano Fares, (Council for Agricultural Research and Economics
Research Centre for Forestry and Wood Arezzo, Italy)

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Secondly, on 9th of March 2018 at 10.15 in Kreutzwaldi 5-D239 another young researcher from our group, Arooran Kanagendran, will defend his doctoral thesis „Differential regulation of release of leaf stress volatiles: from terpene synthase gene expression to emission responses under heat, ozone and wounding stresses“.

Supervisor: Ülo Niinemets

Opponent: Dr. Johan Fredin Uddling (University of Gothenburg, Sweden)

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Postdoc time awaits! (pic from here)

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