Blue light associated with low phytochrome activity can promote elongation growth as shade-avoidance response: A comparison with red light in four bedding plant species
Blue light associated with low phytochrome activity can promote elongation growth as shade-avoidance response: A comparison with red light in four bedding plant species
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DOI：
10.1016/j.envexpbot.2018.07.021
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发表时间：
2018-11-01
影响因子：
5.7
通讯作者：
Zheng, Youbin
中科院分区：
文献类型：
--
作者：
Kong, Yun;Stasiak, Michael;Zheng, Youbin
探讨蓝光对矮牵牛植株伸长生长的作用方式，（矮牵牛x hybrida，'羽绒被红'），calibrachoa（Calibrachoa x hybrida，'Kabloom Deep Blue'），germany（天竺葵x hortorum，“平托优质鲑鱼”），和金盏花（万寿菊，'Antigua Orange'）在4种光质处理下的生长比较：（1）R，“纯”红光（660 nm），（2）B，“纯”蓝光（450 nm），（3）蓝光（450 nm）。（3）BR，通过将B与低水平的R混合以提供接近9的B/R而产生的“不纯”蓝光;（4）BRF，通过将低水平的远红光添加到BR而产生的“不纯”蓝光，其中红光/远红光接近1。连续（24小时）发光二极管照明与100或50 μ mol m（-2）s（-1）光合光子通量密度在约23摄氏度与上述治疗。光照处理14-20 d后，B处理的冠层高度、主茎长度、节间长度和主茎日伸长速率均高于对照。BR对这些性状的作用与R相似或抑制，而BRF对这些性状的促进作用与B相似。计算的光敏色素光平衡，光敏色素活性的指示，是较高的R（0.89）和BR（0.74）比B（0.49）和BRF（0.63）。添加红光（或远红光）逆转了B（或BR）对伸长生长和光敏色素光平衡的影响，表明蓝光促进伸长生长与较低的光敏色素活性有关。此外，与R或BR相比，B和BRF在50 μ mol m（-2）s（-1）时促进矮牵牛和小花矮牵牛伸长生长的程度大于100 μ mol m（-2）s（-1）。除了促进伸长生长外，B和BRF相对于R或BR降低了侧枝分支数、生物量分配、叶上向性、叶角度和/或叶片叶绿素含量，但增加了单株叶面积、叶柄长度和/或生物量分配，这在不同物种中有所不同。这表明，蓝光促进植物伸长生长与降低光敏色素活性相关，是植物对遮荫的一种不同敏感性的避荫反应。
To explore the action mode of blue light on elongation growth of bedding plants, the plant growth and morphology traits of petunia (Petunia x hybrida, 'Duvet Red'), calibrachoa (Calibrachoa x hybrida, 'Kabloom Deep Blue'), geranium (Pelargonium x hortorum, 'Pinto Premium Salmon'), and marigold (Tagetes erecta, 'Antigua Orange') were compared under four light quality treatments: (1) R, "pure" red light (660 nm); (2) B, "pure" blue light (450 nm); (3) BR, "unpure" blue light created by mixing B with a low level of R to provide B/R approximate to 9; (4) BRF, "unpure" blue light created by adding a low level of far red light to BR with red/far red approximate to 1. Continuous (24-h) light-emitting diode lighting with either 100 or 50 mu mol m(-2) s(-1) photosynthetic photon flux density at approximate to 23 degrees C was used with the above treatments. After 14-20 day of lighting treatment, B promoted elongation growth compared to R, as demonstrated by a greater canopy height, main stem length, intemode length, and daily main stem extension rate. However, BR showed similar or inhibitory effects on these traits relative to R, while BRF exhibited similar promotion effects as B. The calculated phytochrome photoequilibrium, an indication of phytochrome activity, was higher for R (0.89) and BR (0.74) than for B (0.49) and BRF (0.63). Adding red (or far red) light reversed the effects of B (or BR) on elongation growth and the phytochrome photoequilibrium, suggesting that blue light promotion of elongation growth is related to the lower phytochrome activity. Also, B and BRF, when compared to R or BR, promoted elongation growth to a greater degree at 50 than 100 mu mol m(-2) s(-1) for petunia and calibrachoa. In addition to the promoted elongation growth, B and BRF reduced side branch number, biomass allocation to side branches, leaf epinasty, leaf angle, and/or leaf chlorophyll content relative to R or BR, but increased individual leaf area, petiole length, and/or biomass allocation to main stem, which varied with different species. It suggests that the promoted elongation growth by blue light associated with lower phytochrome activity is one of shade-avoidance responses with varying sensitivity among species.