Improving zinc efficiency of cereals under zinc deficiency
Improving zinc efficiency of cereals under zinc deficiency
复制标题
DOI：
--
复制
发表时间：
2005-01
期刊：
影响因子：
1
通讯作者：
B. Singh;S. Natesan;Brijendra Singh;K. Usha
中科院分区：
文献类型：
--
作者：
B. Singh;S. Natesan;Brijendra Singh;K. Usha
世界农业中最广泛的非生物胁迫之一源于钙质土壤（尤其是谷物）中锌 (Zn) 的可用性低。谷物品种的锌效率 (ZE) 差异很大，本文中的锌效率定义为植物在缺锌情况下生长和丰产的能力。 ZE 主要归因于在土壤锌利用率较低的条件下获取锌的效率，而不是归因于其在植物内的利用或（重新）转移。此外，更高的锌获取效率可能是由于以下任一或全部原因：有效的离子锌吸收系统、更好的根系结构，即具有有利于从较大土壤体积中利用锌的结构的长而细的根、根部更高的锌动员植物铁载体的合成和释放以及锌-植物铁载体复合物的吸收。种子锌含量也被认为会影响 ZE。本文试图批判性地审视有关全球锌缺乏状况的稀少且分散的报告；谷物 ZE 调节的形态学、生化和生理学基础，以及在锌利用率较差的条件下提高谷物生产力和谷物锌生物利用度方面的 ZE 的方法。重要的含锌酶之间的因果关系，即。据报道，小麦和其他谷物物种具有碳酸酐酶 (CA)、铜/锌超氧化物歧化酶 (SOD) 活性和 ZE。提高铁动员植物金属载体（PS）的产生和释放，是与谷物物种适应缺锌相关的另一种机制。
One of the widest ranging abiotic stresses in world agriculture arises from low zinc (Zn) availability in calcareous soils, particularly in cereals. Cereal species greatly differ in their zinc effici ency (ZE), defined in this article as the ability of a plant to grow and yield well under Zn deficiency. ZE has been attributed mainly to the effi - ciency of acquisition of Zn under conditions of low soil Zn availability rather than to its utilization or (re)-translocation within a plant. A higher Zn acquisition efficiency, further, may be due to either or all of the following: an efficient ionic Zn uptake system, better root architecture, i.e. long and fine roots with architecture favouring exploitation of Zn from larger soil volume, higher synthesis and release of Zn-mobilizing phytosiderophore by the roots and uptake of Zn-phytosiderophore complex. Seed Zn content has also been suggested to affect ZE. This article attempts to examine critically the scanty and scattered reports available on the status of Zn defi ciency globally; morphological, biochemical and physiological basis of regulation of ZE in cereals and approaches to improve ZE in terms of grain productivity and grain Zn vis-a-vis its bioavailability under conditions of poor Zn availability. A causal relationship between important Zn-containing enzymes, viz. carbonic anhydrase (CA), Cu/Zn-superoxide dismutase (SOD) activities and ZE is reported in wheat and other cereal species. Enhanced production and release of Fe-mobilizing phytometallophores known as phytosiderophores (PS), is another mech anism relevant for cereal species in adaptation to zinc deficiency.