Reduction of dark chilling stress in N-fixing soybean by nitrate as indicated by chlorophyll a fluorescence kinetics.
Reduction of dark chilling stress in N-fixing soybean by nitrate as indicated by chlorophyll a fluorescence kinetics.
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DOI：
10.1111/j.0031-9317.2004.0312.x
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发表时间：
2004-06
影响因子：
6.4
通讯作者：
P. D. V. Van Heerden;R. Strasser;G. Krüger
中科院分区：
文献类型：
--
作者：
P. D. V. Van Heerden;R. Strasser;G. Krüger
低于15摄氏度的次优夜间温度（黑暗冷却）经常降低大豆[Glycine max（L.）[梅里尔]生产。硝酸盐的应用是已知的，以减轻一些根区温度低的负面影响，可能是通过抵消抑制所造成的共生固氮（SNF）下降。然而，在田间条件下，暗冷往往不伴随着低根区温度。在这些条件下，硝酸盐可能会增加黑暗的低温耐受性的可能性仍然在很大程度上未被探索。除了通过质体时程指数量化营养体发育外，还记录了在缺乏低根区温度的情况下暴露于黑暗低温期间和之后，在对比耐冷性的大豆基因型中的O-J-I-P（O-I（1）-I（2）-P）叶绿素a荧光瞬变。接种固氮菌日本慢生根瘤菌的植株在添加和不添加硝酸盐的条件下生长。记录的O-J-I-P叶绿素a荧光瞬变通过所谓的JIP测试进行分析，该测试将这些瞬变中的应力诱导的改变转化为生物物理参数的变化，该生物物理参数量化通过光系统II（PSII）的能量流。这些参数之一，性能指数（PI（ABS）），结合了三个主要的功能步骤（光能吸收，激发能捕获，激发能转换为电子传递）的光合活性的PSII反应中心复杂成一个单一的多参数表达。通过使用PI（ABS），我们可以令人信服地表明，硝酸盐的补充大大提高了植物的耐暗冷性和恢复能力，在没有低根区温度。低温敏感基因型（“Java 29”）的低温敏感性更高，表明SNF对低温的反应可能是导致耐冷性基因型差异的重要因素。我们的结果证实了以前的报道，上级耐冷基因型'枫箭'，耐冷性。结果表明，光化学指数（ABS）是一个比初级光化学最大量子产额（F（V）/F（M））更敏感的暗冷胁迫指标。
Sub-optimal night temperatures below 15 degrees C (dark chilling) frequently reduce soybean [Glycine max (L.) Merrill] production. Nitrate application is known to alleviate some of the negative effects of low root zone temperatures, probably by counteracting the inhibition caused by decreased symbiotic nitrogen fixation (SNF). Under field conditions, however, dark chilling is frequently not accompanied by low root zone temperatures. The possibility that nitrate might increase dark-chilling tolerance under these conditions is still largely unexplored. In addition to quantifying vegetative development by means of the plastochron index, O-J-I-P (O-I(1)-I(2)-P) chlorophyll a fluorescence transients were recorded in soybean genotypes of contrasting chilling tolerance during and following exposure to dark chilling in the absence of low root zone temperatures. Plants, inoculated with the N(2)-fixing bacteria, Bradyrhizobium japonicum, were grown with and without nitrate supplementation. The recorded O-J-I-P chlorophyll a fluorescence transients were analysed by the so-called JIP-test which translates stress-induced alterations in these transients to changes in biophysical parameters that quantifies the energy flow through photosystem II (PSII). One of these parameters, the performance index (PI(ABS)), combines the three main functional steps (light energy absorption, excitation energy trapping, and conversion of excitation energy to electron transport) of photosynthetic activity by a PSII reaction centre complex into a single multiparametric expression. By using the PI(ABS) we could convincingly show that nitrate supplementation considerably enhances dark-chilling tolerance and recovery capacity of plants in the absence of low root zone temperatures. This was especially true for the chilling-sensitive genotype ('Java 29'), suggesting that the response of SNF to dark chilling might be an important factor contributing towards genotypic differences in chilling tolerance. Our results corroborated previous reports about the superior chilling tolerance of 'Maple Arrow', a chilling-tolerant genotype. The results obtained indicated that the PI(ABS) is a far more sensitive indicator of dark-chilling stress than the maximum quantum yield of primary photochemistry (F(V)/F(M)).