Expression of antisense SnRK1 protein kinase sequence causes abnormal pollen development and male sterility in transgenic barley

Abstract

SummaryA chimaeric gene was constructed comprising a wheat high molecular weight glutenin subunit gene promoter, a 304-bp sucrose non-fermenting-1-related (SnRK1) protein kinase sequence in the antisense orientation, and the cauli¯ower mosaic virus 35S RNA gene terminator. Transgenic barley plants containing the antisense SnRK1 chimaeric gene were produced by particle bombardment of barley immature embryos with the aim of obtaining plants expressing the antisense SnRK1 sequence in the seeds. Despite the fact that the promoter was expected to be active only in seeds, two independent transgenic lines were found to fail to transmit the transgene to the T 1 generation. These T 0 plants had matured and died before this was discovered, but subsequently four other independent transgenic lines were found to be affected in the same way. Cytological analysis of the pollen grains in these lines showed that about 50% were normal but the rest had arrested at the binucleate stage of development, were small, pear-shaped, contained little or no starch and were non-functional. The presence of antisense SnRK1 transcripts was detected in the anthers of the four lines analyzed and a ubiquitin promoter/UidA (Gus) gene, one of the marker genes codelivered with the antisense gene, was found to be expressed only in the abnormal pollen. Expression analyses con®rmed that SnRK1 is expressed in barley anthers and that expression of one class of SnRK1 transcripts (SnRK1b) was reduced in the abnormal lines. All of the abnormal lines showed approximately 50% seed set, and none of the transgenes were detected in the T 1 generation.

Biochemical and Functional Characterization of PKS11, a Novel Arabidopsis Protein Kinase

“…The molecular mechanisms by which plant cells sense sugars and transduce the signals are not well understood. Plant SnRK1 protein kinases are orthologs of yeast SNF1 and have been implicated to regulate carbon metabolism through both gene expression and direct control of enzyme activation state (48). The involvement of a PKS protein in sugar signaling is unexpected as the PKS family of kinases is known to interact with the SOS3 family of calcium-binding proteins, and as such are involved in calcium signaling (3).…”

The Energy-Signaling Hub SnRK1 Is Important for Sucrose-Induced Hypocotyl Elongation

“…Although KIN10 activity is regulated posttranslationally by Tre6P (Zhang et al, 2009), KIN10 overexpression alone alters the abundance of energy-response transcripts in protoplasts (Baena-González et al, 2007). We used KIN10 overexpression rather than knockouts, because KIN10/11 double knockouts disrupt pollen production and are lethal (Zhang et al, 2001;BaenaGonzález et al, 2007). We also used hypomorphic Targeted Induced Local Lesions In Genomes (TILLING) mutants with reduced TPS1 activity (tps1-11, tps1-12; Gómez et al, 2006Gómez et al, , 2010, which is preferable to tps1 lossof-function mutants that cause seedling developmental arrest (Gómez et al, 2006).…”

The SnRK1A Protein Kinase Plays a Key Role in Sugar Signaling during Germination and Seedling Growth of Rice

“…SnRK1s are proposed to be directly or indirectly involved in the control of carbohydrate metabolism, starch biosynthesis, fertility, organogenesis, senescence, stress responses, and interactions with pathogens (Polge and Thomas, 2007). A potato (Solanum tuberosum) SnRK1 was shown to be involved in starch accumulation (Purcell et al, 1998;, and SnRK1 silencing caused abnormal pollen development and male sterility in transgenic barley (Hordeum vulgare) (Zhang et al, 2001). These studies suggest that plant SnRK1 may play roles in the regulation of global metabolism in plants; however, the detailed mechanism by which SnRK1 regulates its downstream target gene expression, and the precise physiological functions of SnRK1 in plant growth and development, remain elusive.…”