The amino acid, proline, is utilized by different organisms to offset cellular imbalances caused by environmental stresses. The wide use of proline as a stress adaptor molecule indicates that proline has a fundamental biological role in stress response. A comprehensive analysis of the transcript abundance of proline metabolizing genes is fundamental for the assessment of function and regulation of each gene. Using available microarray data and quantitative real-time RT-PCR, the expression profiles of gene encoding key proline biosynthesis and degradation enzymes i.e., OAT, P5CS, P5CR and PDH were examined. Interestingly, validation of candidate genes in rice using in-silico data provided strong evidence for their involvement in stress response. Note that, OsOAT, OsP5CS1, OsP5CS2, OsP5CR showed similar expression pattern in quantitative real-time RT-PCR results as compared to microarray data. However, OsPDH showed a different expression pattern which may be due to the genotypic variation. Furthermore, a biochemical assay measuring proline content gave us a proper indication of the accumulation of proline under stressed conditions. Identification of key proline metabolizing genes from rice and Arabidopsis provides insights on the molecular regulation of proline homeostasis, to initiate metabolic engineering to develop stress-resilient plants.

氨基酸脯氨酸被不同的生物用来抵消由环境压力引起的细胞失衡。脯氨酸作为应激衔接分子的广泛使用表明脯氨酸在应激反应中具有基本的生物学作用。全面分析脯氨酸代谢基因的转录本丰度是评估每个基因的功能和调控的基础。使用可用的微阵列数据和定量实时RT-PCR，检查了编码关键脯氨酸生物合成和降解酶即OAT、P5CS、P5CR和PDH的基因的表达谱。有趣的是，使用计算机验证水稻中的候选基因数据为他们参与压力反应提供了强有力的证据。请注意，与微阵列数据相比，OsOAT、OsP5CS1、OsP5CS2、OsP5CR在定量实时 RT-PCR 结果中显示出相似的表达模式。然而，OsPDH显示出不同的表达模式，这可能是由于基因型变异。此外，测量脯氨酸含量的生化测定为我们提供了在压力条件下脯氨酸积累的适当指示。从水稻和拟南芥中鉴定关键的脯氨酸代谢基因为脯氨酸稳态的分子调控提供了见解，以启动代谢工程以开发抗逆性植物。