[Functional Characterization of ZmHAK1 Promoter and Its Regulatory Transcription Factors in Maize]

Potassium (K^(+)) deficiency in the soil may seriously affect the yield and quality of plants, which usually satisfy their potassium requirements by engaging their K^(+) transporters and/or channels. High-affinity potassium transporter (ZmHAK) family members play crucial role in the uptake and distribution of K^(+) in maize (Zea mays L.). Here, we describe the function of ZmHAK1 promoter and its upstream regulatory transcription factors in maize. In this plant, HAK gene family includes 34 protein-encoding members, with their phylogenetic tree analysis showing both evolutionary conservativeness and diversity. ZmHAK1 gene promoter contains many functional elements related to abiotic stress. Reporter construct pCambia1301:ProZmHAK1:GUS shows that the ZmHAK1 gene is active in the roots, stems, and leaves. Using yeast one-hybrid experiment, we showed that the ZmHAK1 promoter interacts with the transcription factors ZmRAP2.11 and ZmARF2, and that these interactions occur on different fragments of the ZmHAK1 promoter. Transcription factor ZmRAP2.11 localizes in the nucleus, while ZmARF2 is found both in the nucleus and in the cell cytoplasm. In conclusion, our results suggest that the ZmHAK1 regulation has an important role in the process of absorbing potassium ions, and possibly in the response of maize to abiotic stress.

[Pollen morphology of bee plants in Changbai Mountain area]

OBJECTIVE

To develop and utilize the bee plants and bee products in Changbai Mountain area, the representative area of alpine plants in northeast China featuring abundant resources of bee plants.

METHOD

The pollen of bee plants was observed and studied by LM and SEM.

RESULT

The pollen is morphologically oblate, suboblate, spheroidal and prolate. The external sculpture is commonly reticulate, striate and echinulate.

CONCLUSION

Plant pollen identification criteria have been furnished for the development of bee plant resources as well as the inspection of bee products in Changbai Mountain area.