Activity and protein level of AO isoforms in pea plants (Pisum sativum L.) during vegetative development and in response to stress conditions

Abstract

Among three AO isoforms detected in pea plants, the activity of PAO-1 was dominant in leaves of seedlings and young leaves of mature plants, while PAO-3 revealed the highest band intensity in old leaves and roots. PAO-1 and PAO-3 are homodimers consisting of 145 kDa and 140 kDa subunits, respectively, while PAO-2 is a heterodimer of one 145 kDa and one 140 kDa subunit. In leaves, the activity of PAO-1 disappeared gradually with leaf ageing, while in roots it was present only in seedlings but not in mature pea plants. PAO-3 could oxidize abscisic aldehyde, a precursor of abscisic acid, indicating the possible involvement of this isoform in ABA synthesis in pea. The ability of PAO-3 to oxidize abscisic aldehyde was higher in old leaves than in young ones and increased significantly both in roots and leaves of plants exposed to salinity and ammonium treatments. A marked increase of the AO protein level was observed after ammonium application but not under salinity. Interestingly, the activity of PAO isoforms may be transcriptionally and post-transcriptionally regulated during vegetative growth and in response to stress conditions, and such a regulation might be particularly important to adjust ABA levels to the recent requirements of the plant. The observations suggest that the AO isoforms have different metabolic roles and that the activity and protein level of each isoform is regulated not only by environmental conditions but also through plant developmental stages.

An Aldehyde Oxidase in Developing Seeds of Arabidopsis Converts Benzaldehyde to Benzoic Acid

“…A barley (Hordeum vulgare) AO present in leaves, roots, and seeds was capable of oxidizing a number of aliphatic and aromatic aldehydes (Omarov et al, 1999). Additionally, pea (Pisum sativum) leaves possessed AO activity with indole-3-acetaldehyde and abscisic aldehyde (Zdunek-Zastocka et al, 2004).…”

Chemical Profiling and Gene Expression Profiling during the Manufacturing Process of Taiwan Oolong Tea “Oriental Beauty”

“…The final step of ABA biosynthesis is catalyzed by ABA aldehyde oxidase, which requires molybdenum cofactor. 30) It has been reported that Ntdin functions in molybdenum cofactor biosynthesis 31) and hence, these clones might be involved in ABA biosynthesis. Expression of selected genes during manufacture Expression of up-regulated genes during the manufacturing process was evaluated by RT-PCR.…”

Isolation and Characterization of the Aldehyde Oxidase2 Gene from Arachis hypogaea L.

“…Plant AO belongs to a multigene family (Ando et al 2006;Min et al 2000;Ori et al 1997;Sekimoto et al 1997Sekimoto et al , 1998Zdunek-Zastocka 2008), whose members differ in electrophoretic mobility and subunit composition (Akaba et al 1999;Seo et al 2000b;Koiwai et al 2000;Omarov et al 2003;Zdunek-Zastocka et al 2004) and exhibit broad substrate specificity (Koiwai et al 2000;Akaba et al 1998). Plant AO has only been purified from coleoptiles of maize (Koshiba et al 1996).…”

“…Four cDNAs of AO genes from Arabidopsis (Sekimoto et al 1998), three putative AO genes and two AO pseudogenes from tomato (Min et al 2000;Ori et al 1997), three cDNAs from pea (Zdunek-Zastocka 2008), and one AhAO1 cDNA from peanut ) have been reported. However, isoforms that can efficiently oxidize ABAld to ABA have only been identified in Arabidopsis rosette leaves (AOδ; Seo et al 2000b), barley roots (AO2 and AO3; Omarov et al 2003), and pea roots and leaves (PAO2 and PAO3; Zdunek-Zastocka et al 2004). Among the AO genes, the expression of AAO3, TAO1, and TAO3 was increased rapidly in response to drought stress (Seo et al 2000b;Yesbergenova et al 2005).…”