ESA’s FLEX mission reveals the secret glow of plants

Amazing stuff!

(254) ESA’s FLEX mission reveals the secret glow of plants - YouTube

Wrinkled or smooth? Cell growth mechanics determine shape of plant organs

Amazing stuff!

"When inner and outer cell layers of sepals – the leaf-like plant organs that cover and protect the flower bud before it opens – all grow upward, the organs stay smooth and uniformly stiff, which is optimal for the plant, according to a new study. 

The study ... compared a wild type Arabidopsis plant with a mutant one that grew with wrinkled sepals. For the first time, the researchers were able to image both the inner and outer layers of the sepal to understand factors that controlled smoothness and wrinkles. ..."

From the highlights and abstract:

"Highlights

• Smooth sepal formation requires aligned growth directions and comparable stiffness

• Ectopic expression of AS2 causes buckling of the outer epidermis

• Buckles form due to misaligned growth directions and unequal epidermal stiffness

• Buckling promotes the PIN1 convergence to initiate outgrowths

Summary

Nature exhibits organs of various shapes and forms, ranging from smooth to undulated morphologies.

How cells coordinate their growth to produce smoothly shaped leaves and leaf-like organs such as sepals remains unclear.

We identified a mutant, as2-7D, that exhibits ectopic expression of ASYMMETRIC LEAVES 2 (AS2) on the outer epidermis.

Our analysis reveals that ectopic AS2 expression causes the outer epidermis of as2-7D sepals to buckle during early stages of sepal development.

Buckling is caused by conflicting cell growth directions and unequal tissue stiffness across the epidermal layers.

Overexpression of cyclin-dependent kinase (CDK) inhibitor Kip-related protein 1 (KRP1) in as2-7D aligns the growth directions of the outer epidermal cells along the longitudinal axis, increases the overall stiffness of the outer epidermis, and restores sepal smoothness.

Further experiments suggest that buckling promotes the convergence of auxin efflux transporter protein PIN-FORMED 1 (PIN1) to initiate pointed outgrowths. Thus, we show that growth along the longitudinal axis during early developmental stages and comparable stiffness across both epidermal layers of Arabidopsis thaliana sepals are essential for smoothness, as seen in the wild type.

Our findings suggest that in addition to molecular cues influencing tissue mechanics, tissue mechanics can also modulate molecular signals, giving rise to well-defined shapes."

Wrinkled or smooth? Cell growth mechanics determine shape of plant organs | Cornell Chronicle

Growth directions and stiffness across cell layers determine whether tissues stay smooth or buckle (open access)

Graphical abstract

Figure 1. The ectopic expression of AS2 on the outer epidermal layer disrupts sepal smoothness in as2-7D mutant

Israeli scientists engineer plant seeds to produce milk protein without cows

Good news! Moo! Milk from seeds.

"... a new ... study has brought a step closer to the possibility that plant seeds could manufacture and store one of milk’s most important proteins – the same ones that give milk its nutrition, creamy texture, and cheese-making properties. ..."

From the abstract:

"... Casein is a high-quality protein source containing all amino acids, which are vital for human nutrition, and play a vital role in granting the texture and mouthfeel of dairy products.

Plant-seed production may be an efficient strategy for alternative protein production due to its ability to produce complex proteins, perform post-translational modifications, and be resource-efficient.

Targeting recombinant proteins to specific subcellular compartments plays a crucial role in ensuring proper folding, stability, and accumulation.

To determine the most suitable subcellular compartment for accumulation of bovine β-Casein fused to plant C-terminal Oleosin (CTO-Cas) different signal peptides were tested, directing the chimeric protein to endoplasmic-reticulum, vacuole or to the chloroplast.

These gene constructs were transformed into Arabidopsis using Agrobacterium-mediated transformation by the floral dip technique.

CTO-Cas was successfully detected in transformed seeds which were targeted to the vacuole, measured at 1.26% of the Total Soluble Protein (TSP). Subcellular compartmentation of the vacuole-targeted chimeric protein was determined by Transmitting Electron Microscopy (TEM) using gold-immuno-labeling.

CTO-Cas was detected in spherical bodies, which are not vacuoles.

Major morphological changes were observed in the transgenic seed cells in comparison to WT. Large oil bodies dominated WT seed cells, while seeds expressing CTO-Cas targeted to the vacuole had fewer large oil bodies. Instead, they exhibited numerous small oil bodies alongside dense sub-cellular aggregates only observed in the transgenic seeds.

These aggregates were positively gold-immunolabeled with anti-Casein antibodies as well as anti-oil body associated protein antibodies, suggesting the formation of recombinant CTO-Cas aggregates tightly associated with small oil bodies."

Israeli scientists engineer plants to produce milk protein without cows | The Jerusalem Post "The discovery would thus help overcome a major hurdle in producing real dairy proteins without cows, paving the way for more sustainable dairy ingredients and less climate change."

Microscope Reveals Surprising Milk Protein Clusters in Engineered Seeds (IMAGE)

Subcellular localization of C-term-oleosin fused to β-casein reveals unexpected cytoplasmic accumulation in vacuole-targeted arabidopsis seeds (open access)

Transmission electron microscopy (TEM) of engineered seed cells reveals that, instead of reaching its intended storage compartment, the milk protein formed previously unrecognized structures resembling natural casein micelles clustered near tiny oil bodies. Using gold nanoparticle labeling, researchers captured these novel, protein-rich clusters-visible as distinct dark circles-under high magnification to map their unexpected cellular location

Fig. 1 Schematic maps of the vector constructs used for Arabidopsis seeds genetic transformation, and the plasmid map (pCAMBIA 0309-BAR). (ER), endoplasmic reticulum; (Vac), vacuole; (Chl), chloroplast). Made with Bio Render.

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 amazing ways plants defend themselves

Amazing stuff!

How plants quickly adapt to shifting environmental conditions

Amazing stuff! How agile plants can be!

"... The study ... offers a new understanding of how gene activity directs plant growth, and how quickly plants respond to their environment—with shifting light conditions triggering molecular changes in as little as five minutes. The findings provide insights into how to increase yield and safeguard world food production as climate change shrinks the planet’s arable land. ...
“This paper shows, in high resolution, how plants respond to subtle environmental changes on the cellular level,” ...

“Our study reveals the mechanism in close detail and also shows the rapid nature of the response. We found that when PIF7 is active, it binds to DNA. And our data indicate that this leads to the removal of H2A.Z from the DNA. Subsequently, genes are activated, and then this induces growth, to outcompete the neighboring plants,” ...

The speed of the process was unexpected ... in addition to triggering the stress response within five minutes, the histone landscape also recovered quickly when shade was removed.

“When we removed shade, the levels of H2A.Z at PIF7 target genes went back to normal within 30 minutes,” ..."

"... We found that PIFs [Phytochrome-Interacting Factors] act rapidly to reshape the H2A.Z and H3K9ac epigenetic landscape in response to a change in light quality. ... Thus, we describe a PIF–INO80 regulatory module that is an intermediate step for allowing plants to change their growth trajectory in response to environmental changes."

How plants quickly adapt to shifting environmental conditions - Salk Institute for Biological Studies Salk scientists find that canopy shade from competing plants triggers cellular changes in as little as five minutes

PHYTOCHROME-INTERACTING FACTORs trigger environmentally responsive chromatin dynamics in plants (no public access)