Department of Plant Biochemistry, Faculty of Biology, University of Warsaw, Miecznikowa 1, Warsaw, 02-096, Poland.
Department of Plant Physiology, Institute of Biology, Warsaw University of Life Sciences- SGGW (WULS-SGGW), Nowoursynowska 159, Warsaw, 02-776, Poland.
BMC Plant Biol. 2024 Jul 15;24(1):674. doi: 10.1186/s12870-024-05396-8.
Kale, a versatile cruciferous crop, valued for its pro-health benefits, stress resistance, and potential applications in forage and cosmetics, holds promise for further enhancement of its bioactive compounds through in vitro cultivation methods. Micropropagation techniques use cytokinins (CKs) which are characterized by various proliferative efficiency. Despite the extensive knowledge regarding CKs, there remains a gap in understanding their role in the physiological mechanisms. That is why, here we investigated the effects of three CKs - kinetin (Kin), 6-benzylaminopurine (BAP), and 2-isopentenyladenine (2iP) - on kale physiology, antioxidant status, steroidal metabolism, and membrane integrity under in vitro cultivation.
Our study revealed that while BAP and 2iP stimulated shoot proliferation, they concurrently diminished pigment levels and photosynthetic efficiency. Heightened metabolic activity in response to all CKs was reflected by increased respiratory rate. Despite the differential burst of ROS, the antioxidant properties of kale were associated with the upregulation of guaiacol peroxidase and the scavenging properties of ascorbate rather than glutathione. Notably, CKs fostered the synthesis of sterols, particularly sitosterol, pivotal for cell proliferation and structure of membranes which are strongly disrupted under the action of BAP and 2iP possibly via pathway related to phospholipase D and lipoxygenase which were upregulated. Intriguingly, both CKs treatment spurred the accumulation of sitostenone, known for its ROS scavenging and therapeutic potential. The differential effects of CKs on brassicasterol levels and brassinosteroid (BRs) receptor suggest potential interactions between CKs and BRs.
Based on the presented results we conclude that the effect evoked by BAP and 2iP in vitro can improve the industrial significance of kale because this treatment makes possible to control proliferation and/or biosynthesis routes of valuable beneficial compounds. Our work offers significant insights into the nuanced effects of CKs on kale physiology and metabolism, illuminating potential avenues for their application in plant biotechnology and medicinal research.
羽衣甘蓝是一种多功能十字花科作物，具有健康益处、抗逆性，并且在饲料和化妆品方面具有潜在应用，通过体外培养方法有望进一步提高其生物活性化合物。微繁殖技术使用细胞分裂素（CKs），其具有不同的增殖效率。尽管对 CKs 有广泛的了解，但在理解它们在生理机制中的作用方面仍存在差距。这就是为什么在这里我们研究了三种 CKs-激动素（Kin）、6-苄基氨基嘌呤（BAP）和 2-异戊烯腺嘌呤（2iP）-对羽衣甘蓝生理、抗氧化状态、甾体代谢和体外培养下膜完整性的影响。
我们的研究表明，虽然 BAP 和 2iP 刺激了芽的增殖，但同时降低了色素水平和光合作用效率。所有 CKs 都增加了呼吸速率，这反映了代谢活性的增强。尽管 ROS 的爆发不同，但羽衣甘蓝的抗氧化特性与愈创木酚过氧化物酶的上调和抗坏血酸的清除特性有关，而不是谷胱甘肽。值得注意的是，CKs 促进了甾醇的合成，特别是植物固醇，对于细胞增殖和膜结构至关重要，而 BAP 和 2iP 的作用则强烈破坏了这些结构，这可能是通过上调的磷脂酶 D 和脂氧合酶途径。有趣的是，两种 CKs 处理都促进了 sitostenone 的积累，sitostenone 具有清除 ROS 和治疗潜力。CKs 对 brassicasterol 水平和油菜素内酯（BRs）受体的不同影响表明 CKs 和 BRs 之间可能存在相互作用。
根据所提出的结果，我们得出结论，BAP 和 2iP 在体外引起的效应可以提高羽衣甘蓝的工业意义，因为这种处理可以控制增殖和/或有价值有益化合物的生物合成途径。我们的工作深入了解了 CKs 对羽衣甘蓝生理和代谢的细微影响，为它们在植物生物技术和药用研究中的应用提供了潜在途径。
