Study About Pea Actin MRNA Level In Different Conditions

Actin is an important member of cytoskeleton. Plant actin is encoded by multigene family and contains more than one isoviriant. There are at least three isoactins - PEAc I, PEAc II and PEAcIII in pea (Pisum sativum L .) . The different mRNA level of isoviriants in plant organs suggests their functional diversity.The difference of PEAcI and PEAclII mRNA level in different parts of pea is studied by semi-quantitive RT-PCR and Southern blotting. The change of mRNA level response to the 300mM NaCl and 10mM acelcholine are also reseached by the same method. Beacause the 3'UTR of every actin isoviriants is specific , so it is used as probe of Southern blottingIn flower before blossom, PEAc I is expressed strongly in gynoecia, weakly in androecium ; PEAc III is expressed highest in calyce and lowest in gynoecia; PEAcIII stongly expressed in 14-day tendril, the mRNA level is 1.5 times more than 7-day, 21 day and 28-day respectively; in stem, PEAc HI mRNA level rise slight in mature organ. But the mRNA level of PEAc I in stem and trendril is different from that of PEAcIII . It is deduced that the expression pattern maybe different between PEAc I and PEAc III.NaCl and acelcholine can influence microfilament polymerization .10-day seedling was treated with 300mM NaCI and 10mM acelcholine to study the change of PEAc I and PEAc III mRNA level. The common character of PEAc I and PEAc III response to the two stimulation is: 1. mRNA level of the tow isoactins ascends strongly in short time; 2. during 24 hours, the isoactins mRNA level fluctuated. But the ascending degree and fluctuating frequency of individual isoviriant is different to acelcholine and NaCl stimulation .The regulation mechanism in transcriptional level of PEAc I and PEAc III should be researched farther.