Modification of trehalose-6-phosphate levels in plants

1. A compound which is a trehalose-6-phosphate or trehalose-6-phosphonate precursor of formula (I) or an agriculturally acceptable salt thereof:

wherein:

p is 0 or 1;

R 1 to R 7 independently represent F, N 3 , NR′R″, C 1-4 alkyl, —(C 1-4 alkyl)OH or OH, wherein R′ and R″ independently represent hydrogen or C 1-4 alkyl; and

R 8 and R 9 are the same or different and represent H or a photolabile protecting group, wherein at least one of R 8 and R 9 represents a photolabile protecting group.

2. A composition comprising a compound as defined in claim 1 together with an agriculturally acceptable carrier or diluent.

3. A method of increasing starch production in a plant, which method comprises treating the plant or the locus of the plant with an effective amount of a compound according to claim 1 or a composition according to claim 2 .

4. A method of increasing crop yield, which method comprises treating the crop or a locus of the crop with an effective amount of a compound according to claim 1 or a composition according to claim 2 .

5. A method of reducing the incidence of pre-harvest sprouting of a crop, which method comprises treating the crop or the locus of the crop with an effective amount of a compound according to claim 1 or a composition according to claim 2 .

6. The compound according to claim 1 , wherein the photolabile protecting group is of formula (II):

wherein

ring A represents an aryl or heterocyclic group;

either (i) R 10 and R 11 are the same or different and are selected from hydrogen, C 1-4 alkyl which is unsubstituted or substituted with one or more halogen atoms, —OR′, halogen, —NR′R″ or —CO 2 R′, wherein R′ and R″ are independently selected from hydrogen and C 1-4 alkyl, or (ii) two R 10 groups on adjacent photolabile protecting groups together form a bond and R 11 represents hydrogen, C 1-4 alkyl which is unsubstituted or substituted with one or more halogen atoms, —OR′, halogen, —NR′R″ or —CO 2 R′, wherein R′ and R″ are independently selected from hydrogen and C 1-4 alkyl;

n is 0 or 1; and

R 12 and R 13 are the same or different and are selected from hydrogen, C 1-4 alkyl which is unsubstituted or substituted with one or more halogen atoms, —OR′, halogen, —NR′R″ or —CO 2 R′, wherein R′ and R″ are independently selected from hydrogen and C 1-4 alkyl;

wherein X represents a link to the remainder of the compound of formula (I).

7. The compound according to claim 6 , wherein ring A represents a C 6-10 aryl group or a 5- to 14-membered heterocyclic group containing one or more atoms selected from N, O and S, wherein the aryl or heterocyclic group is unsubstituted or substituted with one or more substituents selected from C 1-4 alkyl, —OR′, halogen, CN, —NR′R″,

—COOR′, —(C 1-4 alkyl)COOR′ and —O(C 1-4 alkyl)COOR′, wherein R′ and R″ are independently selected from hydrogen and C 1-4 alkyl, or wherein two adjacent substituents on the aryl or heterocyclic group together form a 5- or 6-membered heterocyclic ring containing one or more heteroatoms selected from N, O or S.

8. The compound according to claim 7 , wherein ring A represents a phenyl, naphthalenyl or dibenzofuranyl ring.

9. The compound according to claim 1 , wherein the photolabile protecting group is of formula (IIa):

wherein

ring A represents an unsubstituted or substituted group selected from phenyl, naphthyl or dibenzofuranyl, wherein a substituted phenyl, naphthyl or dibenzofuranyl group is a phenyl, naphthyl or dibenzofuranyl group having one or two methoxy substituents, or a phenyl, naphthyl or dibenzofuranyl group wherein two adjacent ring positions are substituted with a —CH 2 —O—CH 2 —moiety; and

R 10 represents hydrogen, methyl, —CF 3 or —COOH;

wherein X represents a link to the remainder of the compound of formula (I).

10. The compound according to claim 1 , wherein the photolabile group is selected from

wherein X represents a link to the remainder of the compound of formula (I).

11. The compound according to claim 1 , wherein the photolabile protecting group is of formula (III):

wherein

either Z represents N, Y represents CR 36 and Z and Y are linked by a double bond; or Z represents O, Y represents C═O and Z and Y are linked by a single bond;

R 36 represents —CR 37 R 38 X;

when Y represents CR 36 , R 35 represents hydrogen, and when Y represents C═O, R 35 represents —CR 37 R 38 X;

either (i) R 37 and R 38 are the same or different and are selected from hydrogen, C 1-4 alkyl which is unsubstituted or substituted with one or more halogen atoms, —OR′, halogen, —NR′R″ or —CO 2 R′, wherein R′ and R″ are independently selected from hydrogen and C 1-4 alkyl, or (ii) two R 37 groups on adjacent photolabile protecting groups together form a bond and R 38 represents hydrogen, C 1-4 alkyl which is unsubstituted or substituted with one or more halogen atoms, —OR′, halogen, —NR′R″ or —CO 2 R′ wherein R′ and R″ are independently selected from hydrogen and C 1-4 alkyl;

R 32 represents —OR′, —NR′R″, —O(C 1-4 alkyl)-COOR′, —O(C 1-4 alkyl)-OR′ or —O(C 1-4 alkyl)-NR′R″, wherein R′ and R″ independently represent hydrogen or C 1-4 alkyl; and

R 31 , R 33 and R 34 are independently selected from hydrogen, halogen, —OR′, —NR′R″, —O(C 1-4 alkyl)-COOR′, —O(C 1-4 alkyl)-OR′ or —O(C 1-4 alkyl)-NR′R″, wherein R′ and R″ independently represent hydrogen or C 1-4 alkyl;

wherein X represents a link to the remainder of the compound of formula (I).

12. The compound according to claim 11 , wherein the photolabile protecting group is of formula (IIIa)

wherein

R 32 represents —OR′, —NR′R″ or —O(C 1-4 alkyl)-COOR′, wherein R′ and R″ independently represent hydrogen or C 1-2 alkyl; and

R 33 represents hydrogen, Br, —OR′, —NR′R″ or —O(C 1-4 alkyl)-COOR′, wherein R′ and R″ independently represent hydrogen or C 1-2 alkyl;

wherein X represents the link to the remainder of the compound of formula (I).

13. The compound according to claim 12 , wherein

a) R 33 represents H and R 32 represents OMe, NMe 2 , NEt 2 or —OCH 2 COOH; or

b) R 33 represents Br and R 32 represents OH; or

c) R 33 and R 32 both represent —OCH 2 COOH.

14. The compound according to claim 1 , wherein the photolabile protecting group is selected from

15. The compound according to claim 1 , wherein R 1 to R 7 represent OH.

16. The compound according to claim 1 , wherein p is 1.