Phytoene Phytofluene Accumulation via Ziso Knockout
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Solution Overview
Problem
The amount of phytoene and phytofluene, crucial for their beneficial health effects, is relatively low in carotenoid-producing organisms, necessitating a means to increase their content for enhanced nutritional and protective benefits.
Innovation Solution
Genetically altered organisms with reduced expression or activity of the Ziso protein, specifically through mutations or silencing methods, accumulate elevated levels of phytoene and phytofluene by blocking the carotenoid biosynthetic pathway after zeta-carotene isomerization, achieving up to 25% phytoene and 15% phytofluene of total carotenoid content.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the carotenoid biosynthetic pathway is allowed to proceed normally with functional Ziso protein, then lycopene and downstream carotenoids are produced, but phytoene and phytofluene content remains low
Solution Approach 1:
The patent extracts or removes the Ziso protein function from the carotenoid biosynthetic pathway through genetic modification (knockout or silencing). This extraction of the specific enzymatic function blocks the conversion of zeta-carotene to lycopene, causing accumulation of upstream intermediates phytoene and phytofluene while disrupting the normal pathway functionality.
2Quantity of substance
If Ziso protein expression is reduced or eliminated, then phytoene and phytofluene accumulate to elevated levels, but downstream carotenoid production is blocked
Solution Approach 1:
Instead of enhancing downstream carotenoid production through normal pathway optimization, the patent inverts the approach by blocking the pathway at the Ziso step. This inversion causes retroactive accumulation of upstream compounds (phytoene and phytofluene) that would normally be consumed, thereby achieving high titers of these specific carotenoids at the expense of downstream productivity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The approach results in significantly increased levels of phytoene and phytofluene in genetically modified plants and algae, enhancing their nutritional value and UV protection capabilities.
Implementation Method 1
a specific isomerase, CRTISO, operates in conjunction with ZDS to produce all-trans lycopene
Implementation Method 2
The first committed step in the carotenoid pathway is the head to head condensation of two GGDP molecules to produce phytoene, the first C40 carotenoid, catalyzed by the enzyme phytoene synthase (PSY)
Implementation Method 3
The plant carotene desaturation is a membrane-bound complex reaction sequence. Four double bonds are introduced to phytoene by two enzymes, phytoene desaturase (PDS) and ζ -carotene desaturase (ZDS)
Data Source
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AI summary
The present invention relates to means and methods for modifying the expression of a component in the carotenoid biosynthetic pathway to modify the production of carotenoid towards accumulation of at least one of phytoene, phytofluene, zeta carotene or combinations thereof. The present invention further relates to genetically altered organisms having elevated content of these carotenoids. The present invention further relates to genetically altered organisms having elevated content of these carotenoids, particularly in chromoplast-containing cells.