Plant aquaporins (AQPs) are subdivided into eight groups: PIPs, NIPs, GIPs, HIPs, XIPs, LIPs, TIPs, and SIPs. However, the genetic function and physiological mechanisms of the SIP group in abiotic stress response in plants remains unknown. In this study, we cloned and characterized a banana SIP group AQP gene, designated MaSIP2-1. MaSIP2-1 showed upregulation after osmotic, salt, and cold treatments. Overexpression of MaSIP2-1 in bananas resulted in smaller leaf area and lower plant height than wild-type (WT) plants under normal growth conditions. Lines over-expressing MaSIP2-1 showed increased tolerance to drought and cold stresses, demonstrating that transgenic lines had higher content of chlorophyll, proline, soluble sugar, and abscisic acid (ABA), but lower levels of ion leakage (IL), malondialdehyde (MDA), H₂O₂, and gibberellins (GAs), than WT after drought, cold, and recovery conditions. Moreover, transgenic lines had higher expression of ABA biosynthetic and responsive genes than WT under drought and cold conditions. Taken together, our results show that MaSIP2-1 plays a positive role in dwarfing and tolerance to drought and cold stresses through improved osmotic adjustment, less membrane injury, and changes in ABA and GA levels. Therefore, MaSIP2-1 has the potential for utilization to improve abiotic stress tolerance in crop breeding.

植物水通道蛋白（AQP）分为八类：PIP，NIP，GIP，HIP，XIP，LIP，TIP和SIP。然而，SIP组在植物非生物胁迫反应中的遗传功能和生理机制仍然未知。在这项研究中，我们克隆并鉴定了香蕉SIP组AQP基因，命名为MaSIP2-1。渗透，盐和冷处理后，MaSIP2-1显示出上调。在正常生长条件下，香蕉中MaSIP2-1的过表达导致叶面积和野生高度（WT）植物都比野生型（WT）小。过表达MaSIP2-1的品系对干旱和寒冷胁迫的耐受性增强，表明转基因品系的叶绿素，脯氨酸，可溶性糖和脱落酸（ABA）含量更高，但是离子泄漏（IL），丙二醛（MDA）和H ₂ O ₂含量较低和赤霉素（GAs），比干旱，寒冷和恢复条件下的野生动植物更强。此外，在干旱和寒冷条件下，转基因品系比野生型具有更高的ABA生物合成和响应基因表达。综上所述，我们的结果表明，MaSIP2-1通过改善渗透压调节，减少膜损伤以及ABA和GA水平的变化，在矮化和耐受干旱和寒冷胁迫方面发挥积极作用。因此，MaSIP2-1 有潜力用于提高作物育种中的非生物胁迫耐受性。