Biomarker metabolites are of increasing interest in crops since they open avenues for precision agriculture, whereby nutritional needs and stresses can be monitored optimally. Putrescine has the potential to be a useful biomarker to reveal potassium (K+ ) deficiency. In fact, although this diamine has also been observed to increase during other stresses such as drought, cold or heavy metals, respective changes are comparably low. Due to its multifaceted biochemical properties, several roles for putrescine under K+ deficiency have been suggested, such as cation balance, antioxidant, reactive oxygen species mediated signalling, osmolyte or pH regulator. However, the specific association of putrescine build-up with low K+ availability in plants remains poorly understood, and possible regulatory roles must be consistent with putrescine concentration found in plant tissues. We hypothesize that the massive increase of putrescine upon K+ starvation plays an adaptive role. A distinction of putrescine function from that of other polyamines (spermine, spermidine) may be based either on its specificity or (which is probably more relevant under K+ deficiency) on a very high attainable concentration of putrescine, which far exceeds those for spermidine and spermine. putrescine and its catabolites appear to possess a strong potential in controlling cellular K+ and Ca2+ , and mitochondria and chloroplasts bioenergetics under K+ stress.

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钾缺乏时积累的腐胺有什么作用？

生物标记物代谢物在农作物中受到越来越多的关注，因为它们为精密农业开辟了道路，从而可以最佳地监测营养需求和压力。腐胺有可能成为揭示钾缺乏症的有用生物标志物。实际上，尽管还观察到该二胺在诸如干旱，寒冷或重金属的其他胁迫下会增加，但是相应的变化相对较低。由于其多方面的生化特性，已提出了在K +缺乏下腐胺的几种作用，例如阳离子平衡，抗氧化剂，介导的活性氧物种的信号传导，渗透压或pH调节剂。但是，关于腐胺积累与植物中低钾离子利用率之间的具体联系仍然知之甚少，并且可能的调节作用必须与植物组织中发现的腐胺浓度一致。我们假设，腐胺在K +饥饿时大量增加起了适应性作用。腐胺功能与其他多胺（精胺，亚精胺）的区别可能是基于其特异性或（在K +缺乏时更可能相关）基于可达到的非常高的腐胺浓度，远远超过了亚精胺和精胺的浓度。 。腐胺及其分解代谢物似乎在控制K +胁迫下具有控制细胞K +和Ca2 +以及线粒体和叶绿体生物能的强大潜力。腐胺功能与其他多胺（精胺，亚精胺）的区别可能是基于其特异性或（在K +缺乏时更可能相关）基于可达到的非常高的腐胺浓度，远远超过了亚精胺和精胺的浓度。 。腐胺及其分解代谢物似乎在控制K +胁迫下具有控制细胞K +和Ca2 +以及线粒体和叶绿体生物能的强大潜力。腐胺功能与其他多胺（精胺，亚精胺）的区别可能是基于其特异性或（在K +缺乏时更可能相关）基于可达到的非常高的腐胺浓度，远远超过了亚精胺和精胺的浓度。 。腐胺及其分解代谢物似乎在控制K +胁迫下具有控制细胞K +和Ca2 +以及线粒体和叶绿体生物能的强大潜力。