Germination, growth, osmotic adjustment and ionic balance of wheat in response to saline and alkaline stresses
Germination, growth, osmotic adjustment and ionic balance of wheat in response to saline and alkaline stresses
复制标题
小麦对盐碱胁迫的发芽、生长、渗透调节和离子平衡
DOI：
10.1111/j.1747-0765.2009.00406.x
复制
发表时间：
2009-10-01
影响因子：
2
通讯作者：
Yang, Yunfei
中科院分区：
文献类型：
--
作者：
Guo, Rui;Shi, Lianxuan;Yang, Yunfei
比较了盐胁迫和碱胁迫对小麦幼苗萌发、生长、渗透调节和离子平衡的影响，以阐明碱胁迫(高pH)对植物的伤害机制及其对碱胁迫的生理适应机制。盐碱胁迫( ： Na2SO4和NaHCO3：Na2CO3摩尔比分别为1：1)对小麦幼苗萌发、生长、渗透调节和离子平衡的影响。用Geochem-PC程序分析了盐分对营养液中各种离子活度和游离浓度的影响。分析表明，碱胁迫引起除Na+和K+外的磷酸盐和金属离子的大量沉淀，导致离子活性和各种离子的游离浓度急剧下降。与碱胁迫相比，盐胁迫对小麦种子生长和萌发的抑制作用有所减弱。碱胁迫破坏了根系功能、光合色素和膜系统，导致根系活力和光合色素含量严重下降，电解质渗漏急剧增加。大量Na+内流可能是碱应激损伤的主要原因。碱胁迫对无机离子积累的影响强于盐分胁迫。碱胁迫下，地上部Na+急剧增加，NO、−_3和H_2PO_4_−降低，负电荷严重不足。小麦可能通过促进有机酸的合成来弥补无机阴离子的不足，维持细胞内稳定的pH，积累甜菜碱和可溶性糖，以应对液泡中高Na+浓度的渗透胁迫。
The effects of saline and alkaline stresses (from 1:1 molar ratios of NaCl : Na2SO4and NaHCO3: Na2CO3, respectively) were compared on the germination, growth, osmotic adjustment and ionic balance of wheat seedlings to elucidate the mechanism of alkaline stress (high pH) damage to plants and their physiological adaptive mechanism to alkaline stress. The effects of salines on the activity and free concentrations of various ions in nutrient solutions were analyzed with the program GEOCHEM-PC. This analysis showed that alkaline stress caused a heavy precipitate of phosphate and metal ions, excluding Na+and K+, which caused a sharp decrease in ionic activity and in the free concentrations of various ions. The inhibitory effects of saline stress on the growth and germination of wheat seeds were reduced compared with the effects of alkaline stress. Alkaline stress damaged root function, photosynthetic pigments and the membrane system and led to severe reductions in root system activity and in the content of photosynthetic pigments, and to a sharp increase in electrolyte leakage. Massive Na+influx may be the main cause of damage from alkaline stress. The effect of alkaline stress on the accumulation of inorganic ions was stronger than that of saline stress. Under alkaline stress, Na+sharply increased and NO−3and H2PO4−decreased in shoots, which caused a severe deficit in negative charge. Wheat might enhance organic acid synthesis to remedy the shortage of inorganic anions and maintain a stable intracellular pH, and accumulate betaine and soluble sugars to cope with the osmotic stress from the high Na+concentration in the vacuoles.