College of Life Sciences, Hebei Normal University, Shijiazhuang 050024, China.
J Integr Plant Biol. 2012 Aug;54(8):567-76. doi: 10.1111/j.1744-7909.2012.01139.x.
Leaf senescence is induced or accelerated when leaves are detached. However, the senescence process and expression pattern of senescence-associated genes (SAGs) when leaves are detached are not clearly understood. To detect senescence-associated physiological changes and SAG expression, wheat (Triticum aestivum L.) leaves were detached and treated with light, darkness, low temperature (4 °C), jasmonic acid (JA), abscisic acid (ABA), and salicylic acid (SA). The leaf phenotypes, chlorophyll content, delayed fluorescence (DF), and expression levels of two SAGs, namely, TaSAG3 and TaSAG5, were analyzed. Under these different treatments, the detached leaves turned yellow with different patterns and varying chlorophyll content. DF significantly decreased after the dark, ABA, JA and SA treatments. TaSAG3 and TaSAG5, which are expressed in natural senescent leaves, showed different expression patterns under various treatments. However, both TaSAG3 and TaSAG5 were upregulated after leaf detachment. Our results revealed senescence-associated physiological changes and molecular differences in leaves, which induced leaf senescence during different stress treatments.
叶片衰老会在叶片脱落时被诱导或加速。然而，当叶片脱落时，衰老过程和与衰老相关基因 (SAGs) 的表达模式并不清楚。为了检测衰老相关的生理变化和 SAG 的表达，我们对小麦 (Triticum aestivum L.) 叶片进行了离体处理，并对其进行了光照、黑暗、低温 (4°C)、茉莉酸 (JA)、脱落酸 (ABA) 和水杨酸 (SA) 处理。分析了叶片表型、叶绿素含量、延迟荧光 (DF) 和两个 SAGs（即 TaSAG3 和 TaSAG5）的表达水平。在这些不同的处理下，离体叶片呈现出不同模式的黄色，叶绿素含量也不同。在黑暗、ABA、JA 和 SA 处理后，DF 显著下降。在自然衰老叶片中表达的 TaSAG3 和 TaSAG5 在不同处理下表现出不同的表达模式。然而，叶片离体后，两者的表达均上调。我们的研究结果揭示了叶片在不同胁迫处理下衰老相关的生理变化和分子差异，从而诱导了叶片衰老。
