Abstract
Transgenic cassava (Manihot esculenta Crantz, cv MCol22) plants with a 92% reduction in cyanogenic glucoside content in tubers and acyanogenic (<1% of wild type) leaves were obtained by RNA interference to block expression of CYP79D1 and CYP79D2, the two paralogous genes encoding the first committed enzymes in linamarin and lotaustralin synthesis. About 180 independent lines with acyanogenic (<1% of wild type) leaves were obtained. Only a few of these were depleted with respect to cyanogenic glucoside content in tubers. In agreement with this observation, girdling experiments demonstrated that cyanogenic glucosides are synthesized in the shoot apex and transported to the root, resulting in a negative concentration gradient basipetal in the plant with the concentration of cyanogenic glucosides being highest in the shoot apex and the petiole of the first unfolded leaf. Supply of nitrogen increased the cyanogenic glucoside concentration in the shoot apex. In situ polymerase chain reaction studies demonstrated that CYP79D1 and CYP79D2 were preferentially expressed in leaf mesophyll cells positioned adjacent to the epidermis. In young petioles, preferential expression was observed in the epidermis, in the two first cortex cell layers, and in the endodermis together with pericycle cells and specific parenchymatic cells around the laticifers. These data demonstrate that it is possible to drastically reduce the linamarin and lotaustralin content in cassava tubers by blockage of cyanogenic glucoside synthesis in leaves and petioles. The reduced flux to the roots of reduced nitrogen in the form of cyanogenic glucosides did not prevent tuber formation.
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Claims 11
Claim · model-written summary
RNA interference lines had a 92% reduction in cassava tuber cyanogenic glucosides.
- Taxon
- cassava
Manihot esculentae0 - Material
- cv MCol22e0
- Organ / stage
- tuberse0
- Treatment
- RNA interferencee0
- Gene
- CYP79D1 and CYP79D2e0
- Outcome
- cyanogenic glucoside content in tuberse0
- Direction
- reductione0
- Value
- 92%e0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Transgenic cassava (Manihot esculenta Crantz, cv MCol22) plants with a 92% reduction in cyanogenic glucoside content in tubers and acyanogenic (<1% of wild type) leaves were obtained by RNA interference to block expression of CYP79D1 and CYP79D2”
Claim · model-written summary
RNA interference produced acyanogenic cassava leaves with less than 1% of wild-type cyanogenic glucosides.
- Taxon
- cassavaManihot esculentae0
- Material
- cv MCol22e0
- Organ / stage
- leavese0
- Treatment
- RNA interferencee0
- Gene
- CYP79D1 and CYP79D2e0
- Outcome
- acyanogenice0
- Direction
- reductione0
- Value
- <1% of wild typee0
- Comparator
- wild typee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Transgenic cassava (Manihot esculenta Crantz, cv MCol22) plants with a 92% reduction in cyanogenic glucoside content in tubers and acyanogenic (<1% of wild type) leaves were obtained by RNA interference to block expression of CYP79D1 and CYP79D2”
Claim · model-written summary
About 180 independent cassava lines had acyanogenic leaves.
- Taxon
- cassavaManihot esculentat0
- Outcome
- lines with acyanogenic (<1% of wild type) leavese0
- Value
- About 180 independent linese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“About 180 independent lines with acyanogenic (<1% of wild type) leaves were obtained”
t0“Cassava”
Claim · model-written summary
Only a few cassava lines with acyanogenic leaves were depleted of tuber cyanogenic glucosides.
- Taxon
- CassavaManihot esculentat0
- Outcome
- cyanogenic glucoside content in tuberse0
- Qualifier
- Only a fewe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Only a few of these were depleted with respect to cyanogenic glucoside content in tubers”
t0“Cassava”
Claim · model-written summary
Cassava cyanogenic glucosides are synthesized in the shoot apex and transported to the root.
- Taxon
- CassavaManihot esculentat0
- Organ / stage
- shoot apexe0
- Outcome
- cyanogenic glucosides are synthesized in the shoot apex and transported to the roote0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“girdling experiments demonstrated that cyanogenic glucosides are synthesized in the shoot apex and transported to the root”
t0“Cassava”
Claim · model-written summary
Cassava cyanogenic glucosides showed a negative basipetal concentration gradient, highest in the shoot apex and first unfolded leaf petiole.
- Taxon
- CassavaManihot esculentat0
- Organ / stage
- shoot apex and the petiole of the first unfolded leafe0
- Outcome
- concentration of cyanogenic glucosidese0
- Direction
- higheste0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“resulting in a negative concentration gradient basipetal in the plant with the concentration of cyanogenic glucosides being highest in the shoot apex and the petiole of the first unfolded leaf”
t0“Cassava”
Claim · model-written summary
Nitrogen supply increased cassava shoot-apex cyanogenic glucosides.
- Taxon
- CassavaManihot esculentat0
- Treatment
- Supply of nitrogene0
- Outcome
- cyanogenic glucoside concentration in the shoot apexe0
- Direction
- increasede0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Supply of nitrogen increased the cyanogenic glucoside concentration in the shoot apex”
t0“Cassava”
Claim · model-written summary
CYP79D1 and CYP79D2 expression in cassava leaves was preferential in mesophyll cells near the epidermis.
- Taxon
- CassavaManihot esculentat0
- Organ / stage
- leaf mesophyll cellse0
- Gene
- CYP79D1 and CYP79D2e0
- Outcome
- preferentially expressede0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“CYP79D1 and CYP79D2 were preferentially expressed in leaf mesophyll cells positioned adjacent to the epidermis”
t0“Cassava”
Claim · model-written summary
In young cassava petioles, expression was preferential in epidermis, first two cortex layers, endodermis, pericycle and specific parenchyma around laticifers.
- Taxon
- CassavaManihot esculentat0
- Organ / stage
- young petiolese0
- Outcome
- preferential expressione0
Not reportedGene
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“In young petioles, preferential expression was observed in the epidermis, in the two first cortex cell layers, and in the endodermis together with pericycle cells and specific parenchymatic cells around the laticifers”
t0“Cassava”
Claim · model-written summary
Blocking cyanogenic glucoside synthesis in cassava leaves and petioles can drastically reduce tuber linamarin and lotaustralin.
- Taxon
- cassavaManihot esculentae0
- Treatment
- blockage of cyanogenic glucoside synthesis in leaves and petiolese0
- Outcome
- linamarin and lotaustralin content in cassava tuberse0
- Direction
- reducee0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“possible to drastically reduce the linamarin and lotaustralin content in cassava tubers by blockage of cyanogenic glucoside synthesis in leaves and petioles”
Claim · model-written summary
Reduced cyanogenic glucoside transport of reduced nitrogen to cassava roots did not prevent tuber formation.
- Taxon
- CassavaManihot esculentat0
- Outcome
- did not prevent tuber formatione0
- Qualifier
- reduced flux to the roots of reduced nitrogene0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The reduced flux to the roots of reduced nitrogen in the form of cyanogenic glucosides did not prevent tuber formation”
t0“Cassava”
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See all 7 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.