January 16, 2023

🌻 The Week in Botany January 16, 2023

There’s a plan among some Chinese scientists to use parasitic plants to control invasive species. It’s an interesting idea, but leaves a lot of questions. I’m enjoying seeing the papers tackling various problems come out, and this week they looked at the effect soil microbes have on the parasite-host relationship, which is something I definitely would have overlooked.

It’s not just the paper, but the process that I like. Instead of seeing a Big Paper with all the answers, there’s a steady building of small bricks, so that if the parasitic plants are released it will be because of a mountain of small pebbles that have each been independently examined.

Somehow I can’t feel the same enthusiasm for the many many small raindrops that have been falling here this week. I need to work on my zen.

I don’t expect to achieve complete enlightenment in a week, but I’ll share the small botanical bits that I do find in the newsletter at the same time next week.

Alun (webmaster@botany.one)

On Botany One

The geek’s guide to weird and wonderful plants
“Plants continually excite and surprise me” says Michael Perry, but how does Nigel Chaffey feel about Perry’s new book Hortus Curious?

Botanists find a cool way to preserve an endangered plant’s seeds
If you wonder how cool cool is, it’s at least -196 ℃ (-320 ℉).

How does the corpse flower’s scent change over time?
The Titan arum produces a smell like rotting flesh. Now botanists have analysed the chemicals and found that the smell changes over the two days that the plant flowers.s scent change over time?

Botanists say the largest amber-preserved flower is a new species
The flower, first discovered over 150 years ago, has yielded new clues from its pollen.

A parasitic plant can cause an invasive plant’s allies to switch sides
Scaldweed, Cuscuta grovonii, can prevent an invasive plant from using soil microbes to help invade territory – and the parasite can even become more vicious by using those same microbes against its invasive host.

News & Views

Remembering Wallace
Nature Ecology & Evolution celebrates Alfred Russel Wallace on the bicentenary of his birth.

Sleeping Bear Dunes plants disease-resistant saplings in effort to save its beech trees
The latest effort to combat a disease affecting beech trees at Sleeping Bear Dunes National Lakeshore will continue after its initial project was deemed a success.

Global pollinator losses causing 500,000 early deaths a year – study
Insect declines mean reduced yields of healthy foods like fruit and vegetables and increased disease in people.

‘Holy grail’ wheat gene discovery could feed our overheated world
Harvests that form a vital element of the diets of 4.5 billion people are being devastated by global heating. Now research has found a key to create a heat-resistant variety.

I was plant blind, now I see moss everywhere.
I’ve being studying the organisms that live in moss for the past few years and sharing the joy of those microscopic organisms. However, I haven’t given the moss itself such attention.

Indigenous knowledge is key to sustainable food systems
Agricultural sciences have for too long ignored traditional and local knowledge about crop plants and how best to grow them. That must change if the world is to ensure future food security.

Surface plant fungi in Qinghai-Tibetan Plateau
The Qinghai-Tibetan Plateau is the third pole (~4000 m) of the world. The Plateau is covered by a large area of alpine grasslands. Leaf and root surfaces of alpine plants are commonly colonised by numerous fungi. These fungi, including symbiotrophs or pathotrophs, strongly affect the performance of their host plants and ecosystem functions.

Study identifies new levers for controlling plant biochemistry
Plant biochemists at the U.S. Department of Energy's Brookhaven National Laboratory have discovered a new level of regulation in the biochemical "machinery" that plants use to convert organic carbon derived from photosynthesis into a range of ring-shaped aromatic molecules. The research, just published in the journal Science Advances, suggests new strategies for controlling plant biochemistry for agricultural and industrial applications.

First Garden Bridge in The Netherlands opened
A park on legs is how some describe it. The exceptional new pedestrian and cycle bridge in ʼs-Hertogenbosch that connects the historic city centre to the Paleiskwartier (Palace Quarter).

Abstracts written by ChatGPT fool scientists
Researchers cannot always differentiate between AI-generated and original abstracts.

Biodiversity: Fungi are 'underloved and understudied'
Mushrooms aren't known for their ornamental value, but for this scientist they are a thing of beauty.

Planting the seed: the botanist who harnessed the arts to grow Melbourne’s botanic gardens
As he prepares to depart after 10 years at the helm, Tim Entwisle speaks of making the gardens ‘less introverted’ while staying focused on conservation.

Australian bushfires burning hotter, more often in recent decades compared to past millennia
At this point in summer, most of Australia would usually be in the midst of bushfire season. But three La Niña events in a row, producing hefty and sometimes record-breaking downpours, has taken the pressure off parts of the nation.

Unusual bush tomato with ladder-like features discovered in Northern Territory national park
During a nature walk along one of the Northern Territory's most spectacular lookouts, botanist Peter Jobson and his companions were stopped in their tracks by an unusual looking plant.

Scientific Papers

Innate immunity can distinguish beneficial from pathogenic rhizosphere microbiota
For optimal growth and development, hosts depend on their ability to promote healthy symbiotic interactions while restricting pathogen growth. To ask whether hosts can distinguish phylogenetically similar pathogens and beneficial bacteria, Thoms et al. used two closely related plant-associated strains of Pseudomonas fluorescens where one is beneficial and the other exhibits toxin-dependent virulence. They show that while the two strains co-exist in vitro, the beneficial outcompetes that pathogen in planta.

Heritable transgene-free genome editing in plants by grafting of wild-type shoots to transgenic donor rootstocks
Generation of stable gene-edited plant lines using clustered regularly interspaced short palindromic repeats (CRISPR)–CRISPR-associated protein 9 (Cas9) requires a lengthy process of outcrossing to eliminate CRISPR–Cas9-associated sequences and produce transgene-free lines. Yang et al. have addressed this issue by designing fusions of Cas9 and guide RNA transcripts to tRNA-like sequence motifs that move RNAs from transgenic rootstocks to grafted wild-type shoots (scions) and achieve heritable gene editing, as demonstrated in wild-type Arabidopsis thaliana and Brassica rapa.

Altered Organic Matter Chemical Functional Groups and Bacterial Community Composition Promote Crop Yield under Integrated Soil–Crop Management System
Integrated soil–crop management based on crop models and nutrient management designs has proven useful in increasing yields. However, studies on its effects on the chemical composition of soil organic carbon (SOC) and microbial community composition, as well as their linkage with crop yield, are lacking. Li et al. investigated the changes in SOC content, its chemical functional groups, and bacterial communities, as well as their association with crop yield under different farmland management based on four farmland management field trials over 12 years (i.e., FP: farmer practice; IP: improved farmer practice; HY: high-yield system; and ISSM: integrated soil–crop system management).

Cellulose synthesis in land plants
Pedersen et al. provide a comprehensive overview of the structure, function, and regulation of the cellulose synthesis machinery and its regulatory interactors.

Unidirectional single-file transport of full-length proteins through a nanopore
The electrical current blockade of a peptide or protein threading through a nanopore can be used as a fingerprint of the molecule in biosensor applications. However, threading of full-length proteins has only been achieved using enzymatic unfolding and translocation. Yu et al. describe an enzyme-free approach for unidirectional, slow transport of full-length proteins through nanopores. They show that the combination of a chemically resistant biological nanopore, α-hemolysin (narrowest part is ~1.4 nm in diameter), and a high concentration guanidinium chloride buffer enables unidirectional, single-file protein transport propelled by an electroosmotic effect.

Artificial nanovesicles for dsRNA delivery in spray induced gene silencing for crop protection
Spray-Induced Gene Silencing (SIGS) is an innovative and eco-friendly technology where topical application of pathogen gene-targeting RNAs to plant material can enable disease control. SIGS applications remain limited because of the instability of dsRNA, which can be rapidly degraded when exposed to various environmental conditions. Inspired by the natural mechanism of crosskingdom RNAi through extracellular vesicle trafficking, Qiao et al. describe the use of artificial nanovesicles (AVs) for dsRNA encapsulation and control against the fungal pathogen, Botrytis cinerea.

Changing plant functional diversity over the last 12,000 years provides perspectives for tracking future changes in vegetation communities
Plant communities are largely reshaped by climate and the environment over millennia, providing a powerful tool for understanding their response to future climates. Using a globally applicable functional palaeocological approach, we provide a deeper understanding of fossil pollen-inferred long-term response of vegetation to past climatic disturbances based on changes in functional trait composition. Specifically, we show how and why the ecological strategies exhibited by vegetation have changed through time by linking observations of plant traits to multiple pollen records from southeast Australia to reconstruct past functional diversity.

‘Causes of Widespread Foliar Damage from the June 2021 Pacific Northwest Heat Dome: More Heat than Drought’
Most of the Pacific Northwest (PNW, USA) and British Columbia experienced extraordinarily high air temperatures during an extreme heat wave event (“Heat Dome”) in late June of 2021. A recent paper (Klein et al. 2022) used this extraordinary event to link mechanisms of droughtinduced plant mortality (hydraulic failure) to the observed foliar damage. Klein et al. related photographic observations of foliar damage from a variety of tree species and cultivars growing in a botanic garden near Seattle, WA to hydraulic parameters from other studies of the same species. They found relationships between the degree of damage and literature-derived values of P50 - the xylem pressure at which a 50% loss of conductivity occurs.

Shade avoidance in the context of climate change
When exposed to changes in the light environment caused by neighbouring vegetation, shade-avoiding plants modify their growth and/or developmental patterns to access more sunlight. In Arabidopsis (Arabidopsis thaliana), neighbour cues reduce the activity of the photo-sensory receptors phytochrome B (phyB) and cryptochrome 1 (cry1), releasing photoreceptor repression imposed on PHYTOCHROME INTERACTING FACTORs (PIFs) and leading to transcriptional reprogramming. The phyB-PIF hub is at the core of all shade-avoidance responses, whilst other photo-sensory receptors and transcription factors contribute in a context-specific manner.

Licaria ramiroi (Lauraceae), a new species from Western Mexico
Licaria ramiroi, a species endemic to western Mexico, is described and illustrated. The ascription of the new species to Licaria is analysed. It is classified in the subgen. Licaria and is most closely related to L. triandra and L. siphonantha from which it differs by its glabrous vegetative and floral structures, stamens mainly with free anthers and the inner wall of the receptacle sericeous. According to the IUCN criteria, the species is classified as critically endangered.

A dominant-negative avirulence effector of the barley powdery mildew fungus provides mechanistic insight to barley MLA immune receptor activation
mediate plant disease resistance, which is often accompanied by a localized host cell death response. Effectors can escape NLR recognition through various polymorphisms, allowing the pathogen to proliferate on previously resistant host plants. The powdery mildew effector AVRA13-1 is recognized by the barley NLR MLA13 and activates host cell death. We demonstrate here that a virulent form of AVRA13, called AVRA13-V2, escapes MLA13 recognition by substituting a serine for a leucine residue at the C-terminus.

Approaching complete genomes, transcriptomes and epi-omes with accurate long-read sequencing
The year 2022 will be remembered as the turning point for accurate long-read sequencing, which now establishes the gold standard for speed and accuracy at competitive costs. We discuss the key bioinformatics techniques needed to power long reads across application areas and close with our vision for long-read sequencing over the coming years.

Sugar signaling modulates SHOOT MERISTEMLESS expression and meristem function in Arabidopsis
In plants, development of all above-ground tissues is controlled by the shoot apical meristem (SAM) which balances cell proliferation and differentiation to allow life-long growth. To maximize fitness and survival, meristem activity is adjusted to the prevailing conditions through a poorly understood integration of developmental signals with environmental and nutritional information. Lopes et al. show that sugar signals influence SAM function by altering the protein levels of SHOOT MERISTEMLESS (STM), a key regulator of meristem maintenance.

Careers

PhD Position - Plant Sciences / Transcriptome Analyses: Jülich
Field crops (zucchini, squash or pickling cucumbers) are highly exposed to the influence of climate change. The associated extreme temperatures and also drought can negatively affect the yield and also the quality of the fruits. In an interdisciplinary research network, you will investigate the drought tolerance of zucchini cultivars and the influence of drought stress on gene expression, with a particular focus on biosynthetic pathways of secondary plant constituents that can affect both fruit flavor and quality.

Lecturer/Senior Lecturer/Associate Professor in Plant Sciences: Bristol
We are interested in applicants who we can support to build internationally outstanding plant science research programmes in areas linked to our strategic research priority, ‘Transforming sustainable food production’. Research should address one of the highlighted challenges outlined in our School Research Strategy: Molecular mechanisms underpinning agriculture; Pollinators and crops; Combatting the losses in agriculture due to pests and diseases. We are particularly interested in applications from candidates using molecular approaches, who are engaged in or developing industrial partnerships, and can contribute broadly to teaching in molecular biology and plant science.

Research Associate/Fellow (fixed term): Nottingham
A Research Associate/Fellow is required to undertake research as part of a BBSRC-funded grant: “Discovering novel components and mechanisms of plant oxygen-sensing” The successful applicant will use genetical, biochemical and physiological approaches in combination with Mass Spectrometry to understand the biochemical basis of oxygen-sensing in plants and its physiological consequences. This exciting project is a collaboration between biologists and chemists, it builds directly on our previous work identifying and characterising the molecular mechanism of oxygen-sensing in plants though the N-degron pathway of targeted proteolysis (eg. Gibbs et al Nature 2011, Abbas et al Current Biology 2015, Abbas et al Nature 2022).

Postdoctoral Researcher Role of Strigolactones in Striga Infection and Microbiome Recruitment: Amsterdam
You will investigate the effect of changes in the composition of the maize strigolactone blend, through natural variation and genetic modification, on Striga infection and microbiome recruitment.

Senior Lecturer (Associate Professor) in Forest Genetics: Umeå
The subject area for the position is forest genetics, with focus on breeding of conifers in boreal ecosystems. The research addresses both basic and applied questions relevant for the subject area, mainly using Norway Spruce and Scots Pine as model systems. The research focuses on development of tools within quantitative genetics, with possible applications in e.g. improving wood properties and improving adaptation to climate change.