Growth and morphology responses to narrow-band blue light and its co-action with low-level UVB or green light: A comparison with red light in four microgreen species
Growth and morphology responses to narrow-band blue light and its co-action with low-level UVB or green light: A comparison with red light in four microgreen species
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DOI：
10.1016/j.envexpbot.2020.104189
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发表时间：
2020-10-01
影响因子：
5.7
通讯作者：
Zheng, Youbin
中科院分区：
文献类型：
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作者：
Kong, Yun;Zheng, Youbin
为探讨蓝光对植物伸长生长的作用方式，以芝麻菜（Brassica eruca L.，'火箭'）卷心菜（甘蓝，未知品种名称），芥菜（芥菜，'红宝石条纹'），和羽衣甘蓝在4种光质处理下比较了甘蓝型油菜（Brassica napus，'Red Russian'）微绿苗：（1）R，窄带红光（660 nm）;（2）B，窄带蓝光（455 nm）;（3）BU，通过将B与低水平混合而产生的宽带蓝光UVB（310 nm）（约0.7 μ mol m（-2）s（-1））;和（4）BG，通过将B与低水平（约6%）的绿色光（530 nm）混合而产生的宽带蓝光。在上述处理中，在约22 ℃下，使用具有100 μ mol m（-2）s（-1）光合光子通量密度的连续（24小时）发光二极管照明。在光处理7-8天后，与R相比，B促进了伸长生长（即，较长的下胚轴或叶柄，更快的茎延伸），并诱导一些其它典型的避阴反应（例如，较小的子叶，较浅的植物颜色，或更多的生物量分配给茎），这与下胚轴中较长的细胞和子叶中较低的细胞密度有关，但芥菜除外。与B相比，BU处理抑制了芝麻菜和羽衣甘蓝的伸长生长，而BG处理促进了除芝麻菜外的所有物种的伸长生长。若综合考虑所有植株性状，BU和BG效应与B相似，而与R不同。因此，窄带蓝光与红光可以促进伸长生长作为避阴反应在植物和细胞水平，并添加低水平的UVB或绿色光只能轻微改变窄带蓝光促进避阴反应，尽管不同物种之间的敏感性。
To explore the action mode of blue light on plant elongation growth, the growth and morphology traits of arugula (Brassica eruca L., 'Rocket') cabbage (Brassica oleracea, unknown variety name), mustard (Brassica juncea, 'Ruby Streaks'), and kale (Brassica napus, 'Red Russian') microgreens were compared under four light quality treatments: (1) R, narrow-band red light (660 nm); (2) B, narrow-band blue light (455 nm); (3) BU, broad-band blue light created by mixing B with a low level (approximate to 0.7 mu mol m(-2) s(-1)) of UVB (310 nm); and (4) BG, broad-band blue light created by mixing B with a low level ( approximate to 6 %) of green light (530 nm). Continuous (24 -h) light-emitting diode lighting with 100 mu mol m(-2) s(-1) photosynthetic photon flux density was used in the above treatments at approximate to 22 degrees C. After 7-8 days of light treatment, B, compared to R, had promoted elongation growth (i.e., longer hypocotyls or petioles, faster stem extension), and induced some other typical shade-avoidance responses (e.g., smaller cotyledons, lighter plant color, or greater biomass allocation to stem), which was associated with longer cells in the hypocotyls and lower cell density in the cotyledons except for mustard. Compared with B, the elongation growth was inhibited under BU for arugula and kale, but was promoted under BG for all the species except arugula. If considering all the plant traits together, BU and BG effect was similar to B, but different from R. Therefore, narrow-band blue vs. red light can promote elongation growth as a shade-avoidance response at both plant and cell levels, and adding low-level UVB or green light can only slightly change the narrow-band-blue-light-promoted shade-avoidance response, despite varying sensitivity among species.