Cloning and characterization of the SnRK2 gene family from Zea mays

Abstract

The SnRK2 gene family is a group of plant-specific protein kinases that has been implicated in ABA and abiotic stress signaling. We found 11 SnRK2s in maize, assigned names from ZmSnRK2.1 to ZmSnRK2.11 and cloned ten of them. By analyzing the gene structure of all the SnRK2s from Arabidopsis, rice, and maize, we found seven exons that were conserved in length among most of the SnRK2s. Although the C-terminus was divergent, we found seven conserved motifs. Of these, motif 1 was common to all of the SnRK2 genes. Based on phylogenetic analysis using the kinase domain and motif 1, the SnRK2s were divided into three groups. Motifs 4 and 5 were found specifically in group I, and many genes of this group have been confirmed to be induced by ABA. This result suggests that these two motifs mediate the ABA response. The expression patterns of ZmSnRK2 genes were characterized by using quantitative real-time RCR, which revealed that ZmSnRK2 genes were induced by one or more abiotic stress treatments and therefore may play important roles in maize stress responses.

Cloning and characterization of a maize bZIP transcription factor, ZmbZIP72, confers drought and salt tolerance in transgenic Arabidopsis

“…However, no positive interaction was observed between ZmSAPK8 and ZmbZIP72 (data not shown). In maize, there were at least 11 SnRK2 genes identified (Huai et al 2008), which could potentially interact with ZmbZIP72. The exact regulation pattern in maize needs to be further investigated.…”

The ABA signal transduction mechanism in commercial crops: learning from Arabidopsis

“…Different expression patterns of individual PYR/PYL/RCARs and PP2Cs are expected to reduce the numbers of combinatorial interactions in plant cells. In general, transcript levels of the ABA receptors are downregulated under conditions of stress, whereas the abundance of PP2Cs and SnRK2s transcripts is increased (Huai et al 2008;Raghavendra et al 2010;Szostkiewicz et al 2010). Many studies have analyzed the expression pattern of the ABA signaling components during various development stages and under abiotic stresses, which are known to be under ABA regulation.…”

“…The entire SnRK2 family was identified in many crops including rice (Kobayashi et al 2004), maize (Huai et al 2008), sorghum (Li et al 2010), tomato (Sun et al 2011) and grape (Boneh et al 2012a). Additional SnRK2 genes were characterized in soybeans (Monks et al 2001), barley (Yamauchi et al 2002) and wheat Mao et al 2010;Zhang et al 2010Zhang et al , 2011.…”

SnRK2 Protein Kinases—Key Regulators of Plant Response to Abiotic Stresses

“…Expression of W55a was upregulated not only by drought, salt, and exogenously applied ABA, but also by salicylic acid, ethylene, and methyl jasmonate, whereas it was not responsive to cold stress. In maize, expression of SnRK2s genes was enhanced in response to NaCl (ZmSnRK2.3, ZmSnRK2.6, and ZmSnRK2.4), ABA (ZmSnRK2.2, ZmSnRK2.4, ZmSnRK2.5, ZmSnRK2.7, and ZmSnRK2.10), and cold (ZmSnRK2.3, ZmSnRK2.7), whereas expression of some of them (ZmSnRK2.5, ZmSnRK2.6 and ZmSnRK2.9) was suppressed by heat (Huai et al, 2008;Zou et al, 2006). Hyperosmolarity (dehydration and high salinity) induces the expression of four soybean (Glycine max) SnRK2 genes, SPK1, SPK2, SPK3, and SPK4 (serine/threonine protein kinase 1, 2, 3, and 4) (Monks et al, 2001;Yoon et al, 1997).…”

“…Ten members of the SnRK2 family are encoded by the Arabidopsis as well as rice and sorghum genomes (Boudsocq et al, 2004;Kobayashi et al, 2004;Li et al, 2010). Eleven SnRK2s have been identified in maize (Huai et al, 2008), and some SnRK2 representatives were described for tobacco (Kelner et al, 2004), wheat (Anderberg and Walker-Simmons, 1992;Holappa and Walker-Simons, 1995;Mao et al, 2010;Zhang et al, 2010bZhang et al, , 2011, soybean (Monks et al, 2001), fava bean (Li and Assmann, 1996;Li et al, 2000), and algae (Davies et al, 1999;Gonzalez-Ballester et al, 2008).…”