The author greatly appreciates financial support provided by the National Natural Science Foundation of China project, No. 311712494. The author also appreciates the financial support provided by NATP, BARC, Dhaka, Bangladesh. “
“Acid soils are widespread and limit plant production all over the world. They cover 30%–40% of arable land and more than 70% of potential arable land [1]. Constraints to production in acid soils are caused by a combination of lack of essential nutrients, reduced water uptake and mineral toxicity. The initial visual symptom on plant growth is reduced root length [2]. Although approaches such as adding lime, magnesium or calcium to the soil can ameliorate
adverse effects on plant growth, they are both costly and ecologically unsound.
Breeding tolerant cultivars is the most efficient way to cope with soil acidity. Plants vary significantly in acid selleck kinase inhibitor CHIR-99021 molecular weight soil tolerance. Variation in acid soil tolerance makes it possible to breed tolerant cultivars. The success of breeding programs relies on an understanding of the physiology, genetics and gene regulatory information of acid soil tolerance. Decades of study have revealed that the tolerance is due to both internal and external mechanisms. The external mechanism, organic acid exudation, is common in higher plants. Various genes and QTL in different species are responsible for different tolerance mechanisms. Molecular markers have been developed to assist gene cloning and to provide useful resources for marker-assisted Avelestat (AZD9668) selection for breeding tolerant cultivars. This paper reviews recent progress in molecular approaches to improve Al tolerance in plants. Soil pH has significant adverse effects on the availability of plant nutrients [3], solubility of toxic heavy metals [4], soil microorganism activity [5], breakdown of root cells [6], and cation exchange capacity in soils [7]. The toxic effects can be classified as morphological and physiological. Both lead to poor plant development and consequently
yield reduction [8]. Acid soil is a worldwide problem (Fig. 1) mainly located in two belts: viz., the northern belt in the cold humid temperate zone covering North America, South Asia and Russia; and the southern belt in humid high rainfall tropical areas including South Africa, South America, Australia and parts of New Zealand [1]. There are 3950 million ha of arable land affected by soil acidity. It affects about 38% of farmland in Southeast Asia, 31% in Latin America, 20% in East Asia, 56% in Sub-Saharan Africa, and parts of North America [9] and [10]. In the Americas, 1616 million ha is affected, mostly in South America. In Australia and New Zealand, 239 million ha of agricultural land is acidic [11]. In China and India, 212 million ha or 12% of agricultural land is classified as acidic. Acid soils not only cause plant production losses, but also affect plant distribution.