Analysis of the Cold-Responsive Transcriptome in the Mature Pollen of Arabidopsis

Mature pollen is very sensitive to cold stress in chilling sensitive plants To understand the genetic regula non of tolerance to cold stress we analyzed the transcript expression profile m mature pollen of Arabidopsis using Affymetrix GeneChips containing similar to 24 000 genes Expression of 2 127 genes was cold regulated of which 697 genes were upregulated and 1 430 genes were downregulated Further analysis showed that a large number of signal transduction components were significantly affected by cold treatment indicating extensive changes in the gene regulatory networks of mature pollen Many cold responsive genes encode transcription factors suggesting a multitude of transcriptional cascades A number of genes important for the biosynthesis or signaling of plant hormones such as abscisic acid auxin and jasmonate were regulated by cold stress which is of potential importance in coordinating cold tolerance with pollen growth and development In addition 159 mature pollen specific genes that might be involved in pollen viability were also cold regulated Expression of the cold responsive transcripts identified by microarray analysis was confirmed