Dot Blots

Figure 2（b）shows dot hybridization analyses of maize leaf mRNA from different light treatments using 32P-labeled cloned probes.For each previously identified photogene，the relative amounts of complementary RNAs were dramatically enhanced by R.This enhancement effect was largely reversed by immediate subsequent illumination with FR

Table 2 lists the magnitudes of the light-induced changes in RNAs from experiments like that for which dot blots as shown in Figure 2（b）.Differences of about 10%to 20%，were seen between experiments.For example，the amount of RNA complementary to rcL doubled after R illumination compared to the dark control.This is roughly comparable to the 2.4-fold increase in RNA complementary to rcS.R-induced increases in RNA pools complementary to photogenes ranged up to about 3.5 to 3.8-fold.Exposure to FR alone generally had no effect；the increases of about 20%（UORFs 353，473，and rcS）after illumination with FR are probably not significant.Illumination with FR for 5 min immediately following each 1-min exposure to R blocked the effect of R almost completely except for ps2B，cf1BE，rcS，and cab；in these cases，reversal was incomplete.The levels of maize plastid rRNAs exhibit a transitory increase of approximately 10%to 20%after about 3 h of continuous illumination of dark-grown seedlings（Davey J E，Bogorad L，unpublished data）；the slight apparent increase in transcripts of r16（the gene for 16S rRNA）here tends to confirm the earlier observation.

Table 2　Effects of R and FR Light on the Abundance of Transcripts of Light-Induced Plastid and Nuclear Genes of Maize

ⓐEach value is the average of duplicate or triplicate measurements of each RNA in different hybridizations in two or three experiments with dark control as 100%.The variation is from 5 to 20%.ⓑD，dark；R，red light（1 min）；FR，far-red light（5 min）；R/FR，red light（1 min）followed by far-red light（5 min）.For detailed scheme of light treatment［see Figure 2（a）］.(https://www.daowen.com)