Protein Distribution and Stalk Localization Following Temperature Variation in the Growth and Spiking Period of Phalaenopsis

Abstract

Evaluation of the temperature influence of proteins on the growth and spiking periods in Phalaenopsis can be achieved by proteomics. We analyzed protein variations in orchid leaves to elucidate the relationship between temperature change and the spiking process. In the growth period, protein distribution was similar in each leaf of the same orchid specimen. During cooling, the majority of protein activity is related to glycolysis during sugar consumption and carbon fixation during sugar storage. We identified three proteins-phosphoenolpyruvate carboxylase (PEPC), pyruvate phosphate dikinase (PPDK), and ribulose bisphosphate carboxylase (RuBisCO) large chain precursor-that may regulate stalk generation at Leaf 3 in preference to Leaf 4. One regulatory pathway involves the termination of glycolysis through a reduction in phosphoglycerate kinase (PGK) concentration, which prevents the metabolism of sugars. Simultaneously, another pathway stimulates carboxylases, such as PEPC and PPDK, to produce more sugars for stalk generation. These results indicate the possibility of regulation of the spiking process of Phalaenopsis.