Pepper seeds are slow to germinate and emergence is often non-uniform and incomplete, reducing gains from this cash crop. This study investigated the effects of pineapple stem- derived protease (stem bromelain) based priming on pepper seed germination in relation to reserve mobilization (specifically, proteins and amino acids), germination, emergence and plant growth. These parameters were compared across two controls, (1) unsoaked seeds and (2) seeds soaked in deionized water, and seeds soaked in pineapple stem bromelain crude extract (treatment). Seeds were soaked in bromelain crude extract possessing a proteolytic activity of 6.25 tU or deionized water (first control) for 3 h at 35 °C. Light microscopy revealed an abundance of protein bodies in the endosperm of the seeds prior to imbibition. When observed for a period of 96 h, these bodies were progressively degraded, with the rate of this degradation being fastest in bromelain-treated seeds. Quantitative analysis of protein levels confirmed this observation: 17.2 mg proteins/g FW at 120 h after priming in bromelain-treated seeds compared with 22.1 mg/g FW in controls (average). The bromelain treatment also increased levels of free amino acids from 3.9 mg/g FW in the controls to 4.6 mg/g FW after 120 h of imbibition. Germination and emergence percentages were initially higher in bromelain-treated seeds: 92.0% germination in bromelain-treated seeds vs. ~ 52.2% in the controls at 18 d; 100% emergence in protease-treated seeds vs. ~ 72.2% in the controls at 18 d. However, these parameters were comparable across the treatment and the controls at 28 d. Importantly, plant fresh and dry weights were significantly higher when seeds were primed with bromelain. The results suggest the use of bromelain extracts for priming pepper seeds based on their proteolytic activity, since germination is dependent on the availability of crude protein and essential amino acids. The benefits of bromelain seed priming appear to translate into improved seedling growth as well.

辣椒种子发芽缓慢，出苗通常不均匀且不完整，从而减少了这种经济作物的收益。本研究调查了基于菠萝茎衍生蛋白酶（茎菠萝蛋白酶）的引发对与储备动员（特别是蛋白质和氨基酸）、发芽、出苗和植物生长有关的辣椒种子萌发的影响。这些参数在两个对照中进行了比较，（1）未浸泡的种子和（2）浸泡在去离子水中的种子，以及浸泡在菠萝茎菠萝蛋白酶粗提物（处理）中的种子。将种子浸泡在具有 6.25 tU 蛋白水解活性的菠萝蛋白酶粗提取物或去离子水（第一对照）中，在 35°C 下浸泡 3 小时。光学显微镜显示在吸收前种子的胚乳中有丰富的蛋白质体。观察 96 小时后，这些身体逐渐降解，这种降解速度在菠萝蛋白酶处理的种子中最快。蛋白质水平的定量分析证实了这一观察结果：在菠萝蛋白酶处理的种子中引发后 120 小时为 17.2 mg 蛋白质/g FW，而对照组为 22.1 mg/g FW（平均值）。吸收 120 小时后，菠萝蛋白酶处理还将游离氨基酸水平从对照中的 3.9 mg/g FW 增加到 4.6 mg/g FW。菠萝蛋白酶处理种子的发芽和出苗率最初较高：菠萝蛋白酶处理种子的发芽率为 92.0%，而对照组在 18 天发芽率为 52.2%；在 18 天，蛋白酶处理的种子出苗率 100%，而对照组的出苗率约为 72.2%。然而，这些参数在 28 天时在治疗组和对照组中是可比的。重要的，当种子用菠萝蛋白酶引发时，植物的鲜重和干重显着增加。结果表明，菠萝蛋白酶提取物基于其蛋白水解活性用于引发辣椒种子，因为发芽取决于粗蛋白和必需氨基酸的可用性。菠萝蛋白酶种子引发的好处似乎也转化为改善的幼苗生长。