Allantoin is an intermediate product of purine catabolic pathway that helps in nitrogen mobilization in plants. It is ubiquitously present in the plant kingdom and serves as an important N form transported from source to sink. During the recent years, allantoin has emerged as a molecule involved in increasing stress tolerance in plants. Higher allantoin biosynthesis and accumulation in plants is correlated with an increase in different abiotic stress tolerance such as drought, salt, cold, heavy metals and irradiance. Increased allantoin accumulation subsequently activates ABA (abscisic acid) biosynthetic genes which in turn activate its hallmark downstream stress-related genes such as RD26 and 29 (response to desiccation), CAT2 (catalase2), Mn/Fe/Cu/Zn superoxide dismutases and SOS1 (salt overly sensitive 1). External application of allantoin on plants acts as signalling molecule that induces a complex crosstalk between ABA and JA (Jasmonic acid) pathway resulting in increased stress tolerance in plants. Recently, allantoin has been attributed to the role of kin recognition in plants, which highlights its role as a signal molecule that facilitates inter-plant interactions. In this review, we present the up to date understanding of this Nitrogen carrying compound, which has recently emerged as a molecule that plays important roles in abiotic stress tolerance in plants.

尿囊素是嘌呤分解代谢途径的中间产物，有助于植物中的氮动员。它普遍存在于植物界，并作为一种重要的N形式，从源头转移到水槽。近年来，尿囊素已作为一种参与植物抗逆性增强的分子而出现。较高的尿囊素在植物中的生物合成和积累与不同的非生物胁迫耐受性（例如干旱，盐，冷，重金属和辐照度）的提高相关。尿囊素积累的增加随后激活了ABA（脱落酸）生物合成基因，进而激活了其标志性的下游胁迫相关基因，例如RD26和29（对脱水有反应），CAT2（过氧化氢酶2），Mn / Fe / Cu / Zn超氧化物歧化酶和SOS1（盐过于敏感1）。尿囊素在植物上的外用充当信号分子，诱导ABA与JA（茉莉酸）途径之间的复杂串扰，从而增加植物的胁迫耐受性。最近，尿囊素被归因于植物中亲属识别的作用，这突显了尿囊素作为促进植物间相互作用的信号分子的作用。在这篇综述中，我们介绍了对这种含氮化合物的最新了解，该化合物最近作为一种分子在植物的非生物胁迫耐受性中起着重要作用。