Reference "Anaerobiosis and plant growth hormones induce two genes encoding 1- aminocyclopropane-1-carboxylate synthase in rice (Oryza sativa L.)"

Reference ID

5241

Title

Anaerobiosis and plant growth hormones induce two genes encoding 1- aminocyclopropane-1-carboxylate synthase in rice (Oryza sativa L.)

Source

Molecular biology of the cell, 1993, vol. 4, pp. 363-373

Authors (2)

Zarembinski-T-I

Theologis-A

Abstract

The plant hormone ethylene is believed to be responsible for the ability of
rice to grow in the deepwater regions of Southeast Asia. Ethylene production is
induced by hypoxia, which is caused by flooding, because of enhanced activity
of 1-aminocyclopropane-1-carboxylic acid (ACC) synthase, the key enzyme in the
ethylene biosynthetic pathway. We have cloned three divergent members, (OS-
ACS1, OS-ACS2, and OS-ACS3), of a multigene family encoding ACC synthase in
rice. OS-ACS1 resides on chromosome 3 and OS-ACS3 on chromosome 5 in the rice
genome. The OS- ACS1 and OS-ACS3 genes are induced by anaerobiosis and
indoleacetic acid (IAA) + benzyladenine (BA) + LiCl treatment. The anaerobic
induction is differential and tissue specific; OS-ACS1 is induced in the
shoots, whereas OS-ACS3 is induced in the roots. These inductions are
insensitive to protein synthesis inhibitors, suggesting that they are primary
responses to the inducers. All three genes are actually induced when protein
synthesis is inhibited, indicating that they may be under negative control or
that their mRNAs are unstable. The OS-ACS1 gene was structurally characterized,
and the function of its encoded protein (M(r) = 53 112 Da, pI 8.2) was
confirmed by expression experiments in Escherichia coli. The protein contains
all eleven invariant amino acid residues that are conserved between
aminotransferases and ACC synthases cloned from various dicotyledonous plants.
The amino acid sequence shares significant identity to other ACC synthases (69-
34%) and is more similar to sequences in other plant species (69% with the
tomato LE-ACS3) than to other rice ACC synthases (50-44%). The data suggest
that the extraordinary degree of divergence among ACC synthase isoenzymes
within each species arose early in plant evolution and before the divergence of
monocotyledonous and dicotyledonous plants.