Abstract: Calcium-dependent protein kinases play important roles in regulating growth, development and biological synthesis in higher plants. In this study, the function of a wheat calcium-dependent protein kinase, TaCPK34, in regulating the starch synthesis was identified using the barley stripe mosaic virus-virus induced gene-silencing (BSMV-VIGS) technique under field conditions. Our data indicated that expression levels of TaCPK34 gene in BSMV-TaCPK34-infected wheat plants were significantly inhibited by 63.8%～97.8% compared to those in BSMV-GFP-infected wheat plants (negative control) at 15 d, 20 d, 26 d and 30 d after virus inoculation. Starch content, and grain weight, grain length and width in BSMV-TaCPK34-infected wheat plants were also decreased significantly. Scanning electron microscope observation showed that morphology and number of starch granules in grains of BSMV-TaCPK34-infected wheat plants became looser and fewer compared to those of BSMV-GFP-infected wheat plants. These suggested that TaCPK34 could function in regulating starch synthesis of wheat.

Key words: Triticum aestivum L., starch synthesis, calcium dependent protein kinase, BSMV-VIGS

摘要： 钙依赖性蛋白激酶在调控植物发育与物质合成中发挥重要功能。为探讨一个钙依赖性蛋白激酶-TaCPK34在小麦淀粉合成中的功能，利用大麦条纹花叶病介导的基因沉默技术（barley stripe mosaic virus-virus induced gene-silencing, BSMV-VIGS）将该基因沉默，并在田间条件下测定灌浆期间沉默植株籽粒内TaCPK34基因的表达量及成熟籽粒的淀粉性状。结果表明，在花后15 d、20 d、26 d和30 d，BSMV-VIGS-TaCPK34沉默植株中TaCPK34基因表达量受到显著抑制（63.8%～97.8%）；BSMV-VIGS-TaCPK34沉默植株成熟籽粒淀粉含量、千粒重、粒长和粒宽均显著降低(降幅分别为6.0%、7.1%、4.4%和11.0%)；扫描电镜观察发现BSMV-VIGS-TaCPK34 沉默植株成熟籽粒内淀粉粒排列疏松且数量减少。这些研究结果表明TaCPK34在小麦籽粒灌浆期间对籽粒淀粉的合成有重要影响。

关键词: 小麦, 淀粉合成, 钙依赖性蛋白激酶, 大麦条纹花叶病介导的基因沉默