Cytokinin regulation of a soybean pollen allergen gene

Abstract

Cytokinin treatment of suspension-cultured soybean cells stimulated the accumulation of an mRNA, called cim 1, by a factor of ca. 20 within 4 h. Induction of cim 1 mRNA accumulation occurred at benzyladenine concentrations as low as 10(-8) M. Furthermore, cim 1 mRNA accumulation was stimulated in the absence of cytokinin by staurosporine (an inhibitor of protein kinases) and inhibited in the presence of cytokinin by okadaic acid (an inhibitor of protein phosphatases 1 and 2a), suggesting that cim 1 accumulation in response to cytokinin is dependent on cytokinin-induced dephosphorylation of one or more cellular proteins. The deduced amino acid sequence of the cim 1 protein product, derived from the complete nucleotide sequence of a cim 1 cDNA, was 40% identical to that of a perennial rye grass pollen allergen cDNA (Lol Pl). This sequence also indicated that the cim 1 protein product contains a putative signal peptide followed by predominantly hydrophilic residues, consistent with the hypothesis that it is exported to the apoplast.

Expression of an Expansin Gene Is Correlated with Root Elongation in Soybean

“…Nevertheless, expansin transcripts are most abundant in actively growing organs, such as leaf primordia in tomato (Fleming et al, 1997(Fleming et al, , 1999Reinhardt et al, 1998), internodes in rice (Cho and Kende, 1997b), pollen in maize (Zea mays; Cosgrove et al, 1997) and soybean (Crowell, 1994), pistil in tobacco (Pezzotti et al, 2002), fruits in strawberry (Fragaria spp. ; Civello et al, 1999) and tomato (Brummell et al, 1999a(Brummell et al, , 1999b, and coleoptiles in oat , indicating that they are involved in critical developmental processes.…”

Cell Wall Loosening by Expansins

“…This branch of the expansin family consists of three types of sequences from GenBank: (a) group-1 allergens, a protein class that is highly expressed in grass pollen but not in other tissues or species (pollen allergens from ragweed and other species outside the grass family are not homologous with the group-1 allergens); (b) vegetative homologs of the group-1 allergens expressed in grass seedlings (not in pollen), at least seven of which are expressed in young rice plants, based on the EST database; and (c) vegetative homologs of the group-1 allergens expressed in dicots, which, judging from the EST databases, seem to be much less abundantly expressed in dicots than in grasses (we know of only one example from Arabidopsis, and a second homolog from soybean, CIM1, was originally identified in soybean cell cultures as a cytokinin-induced message; Crowell, 1994).…”

Posttranscriptional Regulation of the Sesbania rostrata Early Nodulin Gene SrEnod2 by Cytokinin

“…Okadaic acid is an inhibitor of the protein phosphatases PP1 and PP2B at submicromolar concentrations and of PP2A at higher concentrations (Hunter, 1995). Okadaic acid and staurosporine, a broad-spectrum protein kinase inhibitor (Tamaoki, 1991), were applied at concentrations previously used for inhibitor studies in plants (Dominov et al, 1992;Raz and Fluhr, 1993;Crowell, 1994) to 2-week-old S. rostrata seedlings in the presence or absence of BAP for 4 h. Although okadaic acid and staurosporine are useful tools for studying signal transduction, it should be noted that the nature of their in vivo action is not known, so results obtained using these inhibitors should be interpreted with caution. Okadaic acid was found to abolish SrEnod2 mRNA accumulation in response to BAP and to cause a dramatic decrease in the levels of SrEnod2 mRNA in both BAP-treated and untreated S. rostrata seedlings below levels observed in seedlings not treated with BAP (basal level; Fig.…”

“…mRNA accumulation is enhanced by cytokinins, including those encoded by a wheat protein kinase gene (Sano and Youssefian, 1994), the gene for the small subunit of Rubisco (RbcS) (Flores and Tobin, 1988), the chlorophyll a / b binding protein gene (Cab) (Flores and Tobin, 1988), defense-related genes (Memelink et al, 1987), the PEP carboxylase gene (PepC) (Suzuki et al, 1994), nitrate reductase genes (Lips and Roth-Bejerano, 1969;Dilworth and Kende, 1974;Lu et al, 1990), the pollen allergen gene (Ciml) (Crowell, 1994), the multiple stimulus response gene cDNA (pLS216) (Dominov et al, 1992), genes of the anthocyanin biosynthetic pathway (Deikman and Hammer, 1995), cyclin D homologs (Soni et al, 1995), and genes for a number of unidentified cDNAs (Crowell et al, 1990). It was shown by nuclear run-on assays that the expression of genes encoding PEP carboxylase (Suzuki et al, 1994), nitrate reductase (Lu et al, 1990), chalcone synthase, and dihydrofolate reductase (Deikman and Hammer, 1995) are enhanced primarily at the transcriptional level by cytokinin.…”