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Polyploids – Fast, Tough Plants

Genomes are the “genetic code carriers” of an organism. Polyploidy is the natural occurrence of additional copies of chromosomes per cell.

Most naturally-occurring plant species are “diploid” in that they have two complete sets of homogeneous chromosomes (hence di-ploid) per cell.

Most common food crops such as wheat and potato have been progressively cross-bred from naturally-occurring polyploids to now have multiple copies of their original chromosome sets in each cell. They are “selectively-bred polyploids”.

Polyploids grow faster, tolerate environmental stress better and express a broader range of natural variation than do diploids.

In addition to faster growth rates, variations desirable from a human perspective may include larger mature size; higher yield of biomass, seed or fruit; and heightened tolerance to environmental stressors such as low rainfall, salinity and diverse soil nutrient qualities.

Polygenomics

Polygenomics are “deliberately-created, genotypically stable polyploid species”.

They are deliberately created using the proprietary PolyX™ process.

They are fertile, in that successive generations can be bred from their seed; and stable, in that those generations do not revert to a diploid status and they do not express characteristics outside of the normal range of variation within their natural genetic coding.

Adaptive Polygenomics

Plants will adapt to almost any conditions over time. In Nature, that may take thousands or even millions of years. PolyX™ technology works with the plant’s in-built adaptive mechanisms to deliberately invoke specific characteristics from within a plant’s normal adaptive repertoire, so as to tailor it to a specific environment or outcome.

Adaptive Polygenomics are the outcome of exploiting those in-built adaptive mechanisms, creating new, stable and fertile lines.

Some of the desirable adaptive polygenomic performance characteristics include:

  • Drought tolerance
  • Salt and/or mineral tolerance
  • Fruit size (for example, as in biofuel crops such as Pongamia and Jatropha)
  • Oil profile (as in mustard seed or Camelina)
  • Decreased time to mature size

GMOs and PolyGenomics

Polygenomic species are NOT Genetically Modified Organisms (GMO) either by their nature or by the legal definition of a GMO.

GMOs are created by direct manipulation of gene sequences including the insertion of foreign genes.

Polygenomic plants are created through facilitating and directing a natural process of gene-doubling. Adaptive Polygenomics (plants bred to specifically express desirable characteristics) are created by selectively directing epigenetic changes within the genome.

PolyGenomX techology takes advantage of the plants inbuilt adaptive mechanisms to ensure that the resultant Polygenomic species are self-sustaining, stable, and capable of passing on their superior characteristics to successive generations.

More about the science

In nature Polyploidy is a rare but natural survival response to severe environmental stress exhibited by many plant species. It is believed that this response has driven most plant evolution on Earth since the first, simple photosynthetic organisms appeared.

In the process of polyploidy an individual plant specimen may spontaneously add extra copies of its chromosomes to each cell.

In adding extra chromosomes, the plant significantly increases its photosynthetic efficiency and enhances its ability to respond to those environmental factors which stressed it into responding in this way in the first place.

Those stress factors may include salinity; mineral or nutrient depletion or toxicity in the soil; variations in water availability or quality as with a rising water table (and increased salinity); climate change; and more.

As a result of their enhanced cellular architecture, polyploid trees process carbon dioxide (CO2) via their Calvin Cycle (the complex light-driven chemical reaction that we generally think of as photosynthesis) more efficiently than do diploid trees.

One significant outcome of this increased efficiency is that polygenomic trees fix more atmospheric carbon dioxide as sugars (the building blocks of their woody structure) and are, therefore, faster growing, and simultaneously release more oxygen into the atmosphere.

At the same time, they demonstrate greater environmental robustness and adaptability than their diploid progenitor. In the words of Chief Scientist Malcolm Lamont, “Since the 1930’s polyploidy has been recognised as the predominant force in plant evolution. There have been recent molecular biological break-throughs in epigenetics and evolutionary genetics. From these we have gained a better understanding of how gene duplication, environment and transposable events combine to drive the evolution of new species. Plants, essentially, lock up the majority of the original genome, using a variety of mechanisms, to conserve important physiological  process. The genomic material is then adapts to environmental stressors.”

Epigenetics – How the environment affects access to DNA and therefore controls gene expression.
Evolutionary Genetics – The study of the genetics involved in the compounding genetic changes that enable a population of organisms to successfully adapt to environmental conditions.
Transposable Events – A small segment of DNA moves from one chromosomal position to another within the environmental adaptation.

Polygenomics, PolyGenomX™ and Polyploids

We differentiate between:

  • “polyploids” as being naturally-occuring specimens;
  • “polygenomics” as deliberately-created specimens; and
  • PolyGenomX as the trademarked term we use to describe the technology we use to generate and adapt new polygenomic species, and to rapidly propagate those (and any other) plants.

While polyploids and polygenomics may sometimes result in exactly the same plant, one is a haphazard natural event and the other is a deliberate and directed scientific procedure that works in harmony with Nature to produce new species.

Taken to the next level, to that of “adaptive polygenomics”, we go where Nature would take millenia to go – if She were heading there!

“Adaptive polygenomics“, then, are those polygenomic species in which we invoke the plant’s unexpressed gene sequences to elicit specific performance characteristics from within its potential genetic repertoire to deliver a defined performance outcome.

All polygenomic species are genetically directly related to their parent stock and are not “GMOs” (Genetically Modified Organisms) but are simply more robustly-constructed variants of their “genetically normal” ancestors.

The PolyGenomX Advantage

PolyGenomX trees:

  1. Grow faster (maturing in 1/3rd less time than comparable diploid stock);
  2. Grow larger(achieving about 130% of their parent’s mass in that shorter timeframe); and
  3. Can be adapted to meet specific commercial and/or environmental needs.
  4. Can be propagated rapidly and consistently using PAPS™ (our proprietary PolyGenomX Accelerated Propagation System)

As a result of these factors in combination, PolyGenomX species contribute strongly to boosting profits in plant-related enterprises, and to accelerating outcome for a wide range of environmental non-profit operations. In simple terms they:

5.   Provide a certain performance and profit accelerator for any enterprise.

Proof of Concept

The following is a paraphrase of the Abstract from a scientific paper by Gamage, Prentis, Lowe, Lamont and Schmidt entitled “Comparison of genetic and physiological traits of diploid progenitors and modified polyploid lines of tree species”. Find it here.

(Note: “Polyploid” is the generally accepted scientific term for polygenomic species.)

“ We examined unmodified (diploid) progenitors and modified (putative polyploid) lines of tree species Agathis robusta, Elaeocarpus grandis, and Paulownia tomentosa that were generated by a new laboratory procedure. (developed by Malcolm Lamont)

Potential advantages of polyploid compared with diploid plants include higher growth rate and greater physiological performance and environmental resilience.

Unmodified progenitors and modified clone lines were subjected to three sets of investigations:

  1. verification of polyploidy with flow cytometry,
  2. verification of genome stability using AFLP – a total genomic marker, and
  3. characterisation of plant properties, including leaf anatomy, physiology and growth.

Nuclear DNA content in cells of Elaeocarpus and Paulownia clones (the two species successfully tested) were elevated, consistent with individuals experiencing genome duplication. Variable results occurred in Paulownia clone lines, where one line actually showed a reduction in genomic content.

All clone lines of Agathis, Elaeocarpus, and Paulownia had high genomic stability demonstrating that mass clonal production should result in phenotypically stable clone lines.

However, most clone lines tested had slightly divergent genotypes possibly resulting from slight genome rearrangements and indicating that all clone lines have resulted from an independent polyploidisation process.

The different genotypes also signify that the polyploidisation process may create novel genetic variation.

Under non-limiting growth conditions in the glasshouse, selected Agathis robusta and Paulownia tomentosa clones had overall larger and thicker leaves with greater stomatal aperture, different biochemical properties, increased photosynthetic rates, and in the case of Agathis, significantly higher biomass production than diploid parents.

The physiological and genetic differences between diploid and polyploid clone lines are consistent with those observed in previous studies. Thus, the new procedure for manipulating nuclear DNA content of trees offers opportunities to develop tree species as timber crops with improved performance and environmental resilience.