Plants smell growth rates of other plants and adopt their own growth

Amazing stuff!

"All plants constantly release volatile organic compounds, or VOCs, into the air ... But a new study suggests that healthy plants may also be sniffing out the competition.

Researchers tested three barley varieties with different growth speeds: a slower-growing cultivar ... an intermediate grower ... and a fast-growing one named ... Over 25 days, the team exposed plants to each other’s VOCs and tracked both physical growth and changes in gene activity.

Based on the type of airborne chemicals released by the specimens nearby, the plants grew more or less aggressively. Barley exposed to scents from fast growers bulked up their biomass, while plants surrounded by slower-growing neighbors dialed themselves back too. Being around slower growers boosted stress response pathways, while fast-growing neighbors triggered genes involved in cell growth and DNA replication. ..."

From the abstract:

"Plants continuously emit volatile organic compounds (VOCs), which can influence the physiology and behavior of neighboring plants. While the ecological role of stress-induced VOCs is well established, the function of constitutive VOCs released by undamaged plants in mediating plant-plant interactions remains less understood.

Here, we demonstrate that barley plants can detect the growth rate of undamaged conspecific neighbors through constitutive VOCs and respond by modulating their growth-defense trade-off accordingly.

Exposure to volatiles from cultivars with contrasting growth (slow or fast) triggered distinct shifts in biomass accumulation and gene expression in receiver plants, whereas VOCs from cultivars with similar growth rates had negligible effects.

Transcriptomic analysis revealed cultivar-specific transcriptional reprogramming of growth- and defense-related pathways, suggesting that constitutive VOCs convey information about emitter identity and competitive vigour that receiver plants use to adaptively reallocate resources and prime stress responses in anticipation of competition. These findings uncover a previously unrecognized role of constitutive VOCs as reliable cues of emitter identity and vigor, mediating adaptive responses in neighboring plants under competitive scenarios."

ScienceAdviser

Plants select growth strategies by spying on their neighbors’ scents

Volatiles released by undamaged plants mediate the adaptive growth strategies in neighbors (open access)

Plants that touch each other are more resilient to stress

Amazing stuff!

"New research has found when plant leaves physically touch each other, they seem to form a biological signalling network to warn each other about the upcoming stress. This can boost their resilience to withstand intense light, which is a common environmental challenge. ..."

From the abstract:

"Plants use sophisticated signaling networks to communicate with each other. While this process is thought to support the overall health and resilience of plant communities, it could also reflect eavesdropping between plants used for competition.

Here we reveal that plants that physically touch each other aboveground are more resilient to excess light stress, and that this phenomenon is dependent on the ability of plants to exchange above ground electric and H2O2 signals with each other. Using a mutant that is unable to transfer Ca2+/reactive oxygen species (ROS) signals but can transfer electric signals (hpca1), as a mediator/connector between different plants, we further separate electric from Ca2+/ROS plant-to-plant signals and transcriptional landscapes, and show that the transfer of Ca2+/ROS signals, as well as the function of several Ca2+/ROS-dependent transcripts, is required for excess light stress acclimation.

Our study reveals that plants that live together and physically touch each other establish an above ground community-wide signaling network that enhances their collective resilience to stress."

Plant leaves touching create biological warning network

United we stand: Plants that physically touch each other are more resilient to excess light stress

Fig. 1 Plants that touch each other aboveground are more resilient to excess light stress.

Amazing maize plant communication

Amazing stuff!

"Although plants ... actually chat with each other quite often through volatile organic compounds, electrical signals, and mycorrhizal networks. One of their most common topics of gossip: potential threats.  ... Turns out that maize, one of the world’s most valuable crops, is especially chatty when planted in a crowded field—chemical communication protects the plants from disease and herbivores.

While studying densely planted corn fields, researchers noticed that even though stalks in the inner rows were smaller, they were much safer from herbivores than those on the outskirts. ... In greenhouse experiments, the team found that corn planted in soils that previously had grown the plants close together gained increased resistance to insects, nematodes, and pathogens, too, indicating that the crowded plants had altered the soil they grew in.

Using chemical, physiological, and genetic analyses ... on the corn’s methods: Densely planted shoots release the volatile linalool, which increases production of the hormone jasmonate. Jasmonate goes on to promote the release of benzoxazinoids, which foster a lasting change in the soil microbiome; this leads to both pest protection and hindered growth after only three days of high-density planting. ..."

From the editor's summary and abstract:

"Editor’s summary

Maize plants emit a volatile gas called linalool, which can influence the growth and development of neighboring plants. Guo et al. found that at high planting densities, high linalool concentrations triggered neighboring plants to release benzoxazinoids into the soil (see the Perspective by Schandry and Becker). These compounds cause the soil microbiota to change composition, with knock-on effects for plants that are subsequently grown there. The altered microbiome enhances defense responses to herbivores but reduces plant growth. These findings demonstrate the implications of high planting density on multiple facets of the plant growth environment. ...

Structured Abstract

INTRODUCTION

Planting crops more densely increases overall yields, but it also raises the risk of pest and pathogen outbreaks. Although plants can modify their architecture to adapt to crowded conditions, how they adjust their immune responses remains largely unknown. ...

RATIONALE

Plants release chemical cues, such as volatiles, that inform neighbors of environmental conditions. One such compound, linalool, is a constitutively emitted leaf volatile in maize and other grasses. ...

RESULTS

Field surveys revealed that maize plants in the inner rows of densely planted fields suffered less herbivore damage than those at the edges but that they also had reduced growth. Laboratory soil–transplantation experiments confirmed that soils conditioned by high-density plantings decreased plant biomass while enhancing resistance to insects, nematodes, and pathogens. These effects extended across genotypes and species.

Volatile profiling identified linalool as a key compound increasing with planting density. Exposure of maize to synthetic linalool reproduced the feedback effects, which required the presence of a living plant. Mechanistically, linalool activated jasmonate signaling in roots and up-regulated genes that drive the biosynthesis and exudation of the specialized metabolite HDMBOA-Glc. This exudate reshaped the rhizosphere microbiome, selectively enriching bacteria that suppressed plant growth but increased resistance in subsequently grown plants. Soil sterilization and microbial inoculation confirmed that these microbes were essential for the feedback loop.

In plants grown in linalool-conditioned soil, defense-related signaling, particularly salicylic acid signaling, was up-regulated, whereas growth-promoting metabolic pathways were down-regulated. Plants lacking salicylic acid signaling did not show growth-defense trade-offs, confirming salicylic acid’s role in expressing the feedback-triggered defense.

CONCLUSION

This study uncovers a volatile-triggered feedback mechanism through which maize adapts its defense in crowded environments. The constitutive emission of linalool primes neighboring plants by activating root jasmonate signaling, promoting HDMBOA-Glc exudation, and altering the rhizosphere microbiome. This, in turn, leads to elevated defense and suppressed growth in subsequent plants through salicylic acid signaling. These findings shed light on how plants integrate aboveground cues and belowground processes to optimize defense in high-density settings. Harnessing this natural defense pathway through breeding, microbial inoculants, or synthetic biology could enable the development of crops that are more resilient and require fewer chemical inputs."

ScienceAdviser

Linalool-triggered plant-soil feedback drives defense adaptation in dense maize plantings (no public access)

Model illustrating how dense planting triggers plant-soil feedback to enhance maize resistance.

The underexplored field of below ground plant root communication

Amazing stuff! Apparently, this is a call for more research in this area!

"It’s well established that plants chemically communicate through the air. They emit volatile chemicals that can attract pollinators, repel the plants’ enemies, call for help in battling pests, and even warn nearby plants of danger. But a growing body of evidence suggests essential communication also occurs beneath the soil ...
Research to date suggests that the chemicals secreted by roots can signal growth changes in neighboring plants and even alert them of an impending attack. Plants may also communicate through the specialized fungal networks that can connect their roots, and maybe even soil-dwelling bacteria. ..."

"Plants communicate through chemical signals, which convey information about environmental threats and resource availability, or even trigger defense mechanisms, allowing plants to coordinate responses and optimize their survival strategies. Plant communication encompasses both above ground and below ground interactions. Above ground, plants emit volatile organic compounds that are detected by the above ground organs of neighboring plants. These airborne chemical signals can transfer information to conspecific neighbors about herbivore attack, pathogens, or even the presence of beneficial insects. Although there are multiple examples of above ground plant communication, below ground plant communication represents a similarly captivating phenomenon that has thus far received less exploration."

ScienceAdvisor

Exposing belowground plant communication Root exudation could be harnessed for ecological and applied research

How do Plants Warn Each Other When in Danger? with Palki Sharma

Recommendable! Amazing stuff!

Scientists discover plant hormone that boosts growth by 30%

Amazing stuff! This could have huge implications!

"... agro-microbials—or agro-chemicals of natural origin—that can enhance the synergy between crops and microbes, and ultimately improve crop yield and productivity.

In a five-year study that began in 2018, the scientists discovered that a well-known protective hormone typically released by plants above ground during periods of stress—a volatile organic compound (VOC) known as methyl jasmonate (MeJA)—possessed a hitherto unknown function. They found that MeJa served as a shared, possibly secret, language that allows a plant to communicate with the surrounding layers of microorganisms embedded in the soil.

The research team has made three important discoveries:

1. Using a specially engineered airflow system, scientists have found, for the first time, that MeJA is released underground by the plant roots in a volatile form;
2. The presence of volatile MeJA triggers and enhances the formation of biofilms in bacteria situated at a distance from the plant roots; and
3. These bacteria in the biofilm release a different set of volatile compounds that can boost plant growth by up to 30%. ...

As the world population is projected to reach 10 billion by 2050 [I have my doubts about this projection], ensuring food security for its inhabitants has become one of the most pressing challenges of this century. Singapore, for example, has set a "30 x 30" goal—to be able to produce 30% of our nutritional needs by 2030. ..."

From the abstract:

"The rhizosphere is a niche surrounding plant roots, where soluble and volatile molecules mediate signaling between plants and the associated microbiota. The preferred lifestyle of soil microorganisms is in the form of biofilms. However, less is known about whether root volatile organic compounds (rVOCs) can influence soil biofilms beyond the 2–10 mm rhizosphere zone influenced by root exudates. We report that rVOCs shift the microbiome composition and growth dynamics of complex soil biofilms. This signaling is evolutionarily conserved from ferns to higher plants. Methyl jasmonate (MeJA) is a bioactive signal of rVOCs that rapidly triggers both biofilm and microbiome changes. In contrast to the planktonic community, the resulting biofilm community provides ecological benefits to the host from a distance via growth enhancement. Thus, a volatile host defense signal, MeJA, is co-opted for assembling host-beneficial biofilms in the soil microbiota and extending the sphere of host influence in the rhizosphere."

Scientists discover plant hormone that boosts growth by 30%

NUS-SCELSE scientists uncover plant hormone that can boost plant growth by 30% This exciting discovery holds great promise for sustainable food security across diverse soils and crops

Volatile methyl jasmonate from roots triggers host-beneficial soil microbiome biofilms

Fig. 1: Plant root VOCs promote biofilm formation in the soil microbial community.

The Fascinating Language Of Plants

Trigger

Article “The Secret Language of Plants” published by the Simmons Foundation.

Smarter Animals

In recent years, we have learnt more and more about how many animals are much more intelligent and much more able to communicate even complicated things than a majority of humans ever expected.

Plant Communication

Have we not heard stories before where some people were saying that plants at home would talk to them or plants could get lonely or plants would respond to human suffering/happiness etc.

It appears in recent years more evidence has been discovered that there is something like chemical or even electrical communication going on between plants of the same kind or other kinds (inter and intra plant communication) or between plants and insects.

A Plant Brain?

Since we still do not understand animal or human brains very well how can we rule out that plants have no brain?

Does a plant brain have to function similar to an animal brain?