Overexpression of IAA1 with domain II mutation impairs cell elongation and cell division in inflorescences and leaves of Arabidopsis.

The auxin/indoleacetic acid (Aux/IAA) proteins are negative regulators of the auxin response factors (ARFs) that regulate expression of auxin-responsive genes. The Aux/IAA proteins have four conserved domains. Domain II is responsible for the rapid degradation of these proteins.

A synthetic de-greening gene circuit provides a reporting system that is remotely detectable and has a re-set capacity.

Plants have evolved elegant mechanisms to continuously sense and respond to their environment, suggesting that these properties can be adapted to make inexpensive and widely used biological monitors, or sentinels, for human threats. For a plant to be a sentinel, a reporting system is needed for large areas and widespread monitoring. The reporter or readout mechanism must be easily detectable, allow remote monitoring and provide a re-set capacity; all current gene reporting technologies fall short of these requirements.

Either soluble or plastidic expression of recombinant protoporphyrinogen oxidase modulates tetrapyrrole biosynthesis and photosynthetic efficiency in transgenic rice.

Protoporphyrinogen oxidase (Protox) is the last shared enzyme of the porphyrin pathway. As a continuation of our previous work in which the transgenic rice plants expressing the Bacillus subtilis Protox in the cytoplasm or the plastid showed resistance to diphenyl ether herbicide, this study was undertaken to identify the effects of tertapyrrole biosynthesis in these transgenic rice plants. The transgenic plants either targeted into plastids or expressed in cytoplasm showed higher Protox activity than wild-type plants did.

Molecular characterization of the gene encoding rice allene oxide synthase and its expression.

The gene encoding rice allene oxide synthase, OsAOS, was intronless and had nucleotide sequences with the high GC content of 67%. Deduced amino acid sequences had very high similarity with other AOS proteins, in particular 74% similarity to barley, characterized by the conserved motifs of P450 cytochrome of the CYP74A family. Purified recombinant rice AOS protein expressed in Escherichia coli converted 13-hydroperoxylinolenic acid to allene oxide.