From plant science to gardening

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Spring in my garden

Last week this blog celebrated its third birthday. In that time I have gone from being a research scientist to working as an editor for a scientific journal and so the involvement of plants in my life has changed somewhat. Working with plants was one of my favourite parts of my old role in research and so its perhaps not surprising that I now do quite a bit of gardening in my spare time.

Until about a year ago, the extent of my gardening experience was a few herbs in pots outside and a bunch of low-maintenance houseplants. I wasn’t always very good at looking after these plants, so branching out to a whole, albeit small, garden has all been a bit of an experiment!

I’m happy to say that my gardening experiment has overall been pretty successful so far. I’ve managed to grow some edible vegetables and my garden looks much tidier and more colourful than it did when I moved in. Most importantly, now that I have an office job, I’ve really enjoyed having a good excuse to spend lots of my leisure time outside. However, my first year in the garden hasn’t been completely plain sailing as I ran into a few problems and disasters along the way. Here are the most useful lessons I have learnt along the way:

Be on the alert for pests – they WILL find your favourite plants. Last year, slugs and snails attacked my salad leaves and destroyed the marigolds I was growing. I tried out a few different methods to deter them from eating the rest of my crops and eventually settled on copper tape. Slugs and snails don’t like crawling over copper and so I could use the tape to make a pretty good barrier to defend a lot of my vegetable crops. Unfortunately, the same cannot be said for my nasturtiums (Tropaeolum majus), which became infested with hundreds of blackflies (a type of aphid) and withered and died soon after.

That plant support or structure might look tidy, but will it withstand the weather? I must admit that the first few structures I built to support plants were not all as robust as they should have been because I didn’t really appreciate how windy it would be in my garden. The canes holding up my tomatoes were blown over on several occasions, and the netting structure protecting my cabbages nearly flew away in a winter gale.

When digging in an overgrown patch of ground, keep an eye out for plants you might want to keep. Last year, I got a good crop of potatoes from the handful of tubers left in the vegetable patch by the previous occupants of the house. And just this week I discovered some parsnips growing amongst the grass of the overgrown allotment I’ve recently taken on with some friends. Being fairly hopeless at plant identification, I didn’t know what potato or parsnip plants looked like until I stumbled into them.

Work out what types of plants you like to grow and then grow them. I like to feel “productive” when I’m gardening, so I can spend hours tending to my vegetable patch and then forget to water my houseplants. As a result, I’ve tried to fill as much of my garden with fruit and vegetables as possible, and then used low-maintenance decorative plants to fill in the gaps and really shaded areas.

My main gardening project for this year is to work on an allotment with my friends. The plot hasn’t been cultivated in a few years so was pretty overgrown, but since we took on the tenancy a couple of months ago, we have managed to clear some parts of it and plant some soft fruit crops. Watch this space.

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The new project…

Tracing the roots of an ancient friendship

 

Figure 1

An AM fungus (yellow) contacts the surface of a plant root. The nuclei of the plant cells are visible as blue spots. Image adapted from ref 3. Credit: Andrea Genre and Mara Novero (CC BY 3.0).

Plants need nutrients to be able to grow. Unfortunately, many of these nutrients can be scarce in the soil and therefore hard to get hold of. To get around this problem, most plants are able to form friendly relationships – known as symbioses – with soil microbes that can provide them with certain nutrients in exchange for sugars.

Today, around 80% of land plants form symbioses with a group of fungi known as arbuscular mycorrhizal (AM) fungi (1). Fossil evidence suggests that this symbiosis first emerged around 450 million years ago. This is around the same time that plants first started to colonise land. The transition from water to the dry and harsh environments on land would have presented many challenges to the early land plants, for example, how to avoid losing too much water. Another challenge would have been how to access essential nutrients that their ancestor (a type of green algae) would have gained directly from the water.

The liverworts, hornworts and mosses are thought to be the earliest groups of land plants (2). Since the AM symbiosis is widespread in these groups, it has been suggested that this symbiosis is one of the innovations that helped these primitive plants to survive on land.

Previous studies have identified many plant genes that are needed for AM symbiosis in legumes and other land plants. These genes can be split into two main groups: some are in a signalling pathway needed for the plant and fungus to communicate with each other, and others are activated later to allow the fungus to infect into the roots of the plant. Recently, Pierre-Marc Delaux and colleagues used a technique called phylogenetics to analyse genetic material from many different algae, liverworts, hornworts and mosses with the aim of finding out when the AM symbiosis genes first appeared (2).

Delaux et al. show that these plant genes emerged in stages, starting from before earliest plants colonised land. The signalling pathway genes appeared first, and are present in the algae that are thought to be the closest relatives of land plants, the Charophytes (2). On the other hand, the infection genes appear to be missing from the algae, but are present in the liverworts, hornworts and mosses.

These findings suggest that the algal ancestors of land plants were pre-adapted to interact with fungi. Currently, there is no evidence to suggest that the Charophytes are able to form AM symbioses themselves. Therefore, it is possible the signalling pathway evolved to allow algae to interact with other microbes and was later altered to allow the early land plants to interact with AM fungi.

Reference:

  1. Parniske, M. (2008). Arbuscular mycorrhiza: the mother of plant root endosymbioses. Nat Rev Microbiol, 6, 763-75.
(Good review of AM symbiosis, but unfortunately this article is hidden behind a paywall…)
  2. Delaux P, Radhakrishnan GV, Jayaraman D, Cheema J, Malbreil M, Volkening JD, Sekimoto H, Nishiyama T, Melkonian M, Pokorny L, Rothfels CJ, Sederoff HW, Stevenson DW, Surek B, Zhang Y, Sussman MR, Dunand C, Morris RJ, Roux C, Wong GK-S, Oldroyd GED, Ané JM. 2015. Algal ancestor of land plants was preadapted for symbiosis. Proceedings of the National Academy of Sciences of the United States of America. 2015, DOI: 10.1073/pnas.1515426112, PMID: 26438870
  3. Corradi N, Bonfante P. 2012. The Arbuscular Mycorrhizal Symbiosis: Origin and Evolution of a Beneficial Plant Infection. PLoS Pathog 8(4): e1002600. doi:10.1371/journal.ppat.1002600

The catch-22 of being a carnivorous plant

Guest post by Sonja Dunbar (@PlantSciSonja)

Plants, like any other organism, want to reproduce. The usual way that plants achieve this is known as sexual reproduction, where an egg cell and sperm from two different individuals fuse and then develop into a new plant. However, since plants are generally anchored to one spot, they can’t meet up to reproduce. Instead, they rely on a variety of more indirect methods to transport sperm to other plants. For example, many flowering plants (also known as angiosperms) recruit insect messengers to carry their sperm, safely packaged in pollen grains, from one plant to another. They use colourful, sometimes scented, flowers to attract potential pollinators and often reward them with a sugary drink, nectar, while coating them in the pollen the plant wants them to carry. But what if you are a plant that also eats insects?

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Some of the most well-known pollinators; bees and butterflies. Image credit: S. Dunbar

Carnivorous plants obtain nutrients from trapped insects to help them cope with a lack of important nutrients in their environment, such as nitrogen, that they need to grow (1). There are several different trap types, from snap traps, to flypaper traps and pitfall traps. The fact that carnivorous species are found in multiple different plant families suggests this strategy has arisen several times. Continue reading

On the origin of chloroplasts

Guest post by Joram Schimmeyer

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Chloroplasts in plant cells are easily identified under a microscope by their green colour. Image: J. Schimmeyer.

Of all the biological processes found on Earth, photosynthesis could be considered one of the most important. During photosynthesis, the energy from sunlight is used to build up sugars in the cells of plants, algae and some bacteria. These sugars can then be metabolised by the cells or other organisms that feed on them. Also, photosynthesis produces oxygen gas as a by-product, which is needed by most forms of life on earth. Without photosynthesis, life as we know it would not be possible.

In plants and algae, photosynthesis is carried out in tiny compartments inside cells called chloroplasts. This compartment contains a green pigment called chlorophyll, which is used to harvest light energy and is responsible for plants appearing green in colour. Chloroplasts vary greatly in shape and size, but they are all enclosed by two membranes and filled with even more membranes known as the thylakoid membrane system. The key players of photosynthesis are located within these thylakoid membranes; large groups of proteins use the light energy from chlorophyll to convert carbon dioxide form the atmosphere into sugars. The sugars can then be broken down to provide energy to drive growth and other cellular processes. Continue reading

Thank you

As you may know, my year did not get off to the best start and I’ve been having a bit of a break from blogging.

Thank you to everyone who volunteered to write guest posts during my break. My plea for help with the blog got a much bigger response than I had anticipated and this brightened what was otherwise a very tough time for me. It has been a real treat for me to host articles written by such a variety of different people and covering such different topics. Most of the guest articles are now up but there should be a couple more to come in the next few weeks.

I also want to thank the many other people who spread the word about my hunt for guest bloggers and sent me supportive messages. I feel really lucky to belong to such a supportive online community.

I’m starting to feel the urge to write again so I hope to be able to publish a science post on here in the next week or so. I always enjoy receiving guest posts so please do get in touch if there is something you would like to write about.

An unsustainable trade

Guest post by Isabella Whitworth (@Orchella49).

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Roccella gracilis on wool yarn that has been dyed with orchil made from Lasallia pustulata. Image credit: Isabella Whitworth .

Lichens are complex plant-like organisms made up of a fungus and an alga or cyanobacterium that live together in a mutually beneficial relationship (symbiosis). They are often found attached to rocks or trees and species can vary hugely in appearance, from flat, crusty forms to leaf-like growths. Certain species have been used as dyestuffs for millennia, although not all lichens produce dye.

My research into dye lichens was triggered by a chance mention of ‘an archive in the attic’ by local friends. Their forebears were dye manufacturers in nineteenth century Leeds in the UK and the company archive had been passed down three generations. The company’s initial fortunes came from the successful processing of orchil, a dye made from lichens. Continue reading

Peer mentoring & why you should, too

Guest post by Liz Haswell (@ehaswell)

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Image licensed under CC BY-SA 3.0 NY via Google (author not known).

Mentoring programs are believed to be essential to a successful career in science and are considered a critical step in improving the retention of women and under-represented minorities in science, engineering and technology fields*. Traditional mentoring matches a junior or inexperienced person—the mentee—with someone senior or more experienced—the mentor. The topic of today’s post is a different kind of mentoring, which I am calling “peer mentoring**”. In this case, each participant is both a mentor and a mentee. Over the last 15 years, I have been involved in several different peer-mentoring groups, and in every case they have been a powerful source of personal and professional growth. Here, I explain what I mean by peer mentoring, describe my own experiences, and list some suggestions for starting your own group.

One possible format for a peer-mentoring group is laid out in the book Every Other Thursday: Stories and Strategies from Successful Women Scientists. Ellen Daniell describes her experience as part of a group of women faculty—including beloved University of California, San Francisco (UCSF) professors Carol Gross and Christine Guthrie—as they meet every two weeks to set goals and troubleshoot challenges. Though this book is more memoir than instruction manual, it explains in detail how the group members established a rigorous yet supportive framework that helped them to be as productive as possible during their meetings, and how the work they did in “group” improved their personal and professional lives.  Continue reading