Table I.

ABA biosynthetic genes and their regulation in Arabidopsis

Not all the genes listed are involved in ABA biosynthesis; those known to be involved are indicated in bold. Gene symbols are given in Figure 1.

Genes Arabidopsis Genome Initative Identification Mutants Expression Pattern Stress Inducibility
ZEP At5g67030 aba 1, los6, npq2 Ubiquitous Inducible in roots, also in leaves
SDR1 At1g52340 aba2,gin1, sis4, isi4, sre1, san3 Ubiquitous? Vascular tissues Not induced by stress but by sugar
NCED1/CCD1 At3g63520 Not inducible?
NCED2 At4g18350 Not inducible
NCED3 At3g14440 nced3 Ubiquitous? Strongly inducible
NCED4 At4g19170 Not inducible
NCED5 At1g78390 Not inducible
NCED6 At3g24220 Not inducible
NCED9 At1g30100 Weakly inducible
AAO1 At5g20960 Roots and seeds
AAO2 At3g43600 Roots
AAO3 At2g27150 aao3 Leaves but not siliques/seeds Inducible in leaves but not in roots
AAO4 At1g04580 Mainly in siliques
MCSU At1g16540 aba3, los5, frs1 Ubiquitous Inducible