Root Branching and Nutrient Efficiency: Status and Way Forward in Root and Tuber Crops

Abstract

Plants are immobile organisms that require roots to efficiently and cost-effectively exploit their habitat for water and nutrients. Plant root systems are dynamic structures capable of altering root branching, root angle, and root growth rates determining overall architecture. This plasticity involves belowground plant-root mediated synergies coupled through a continuum of environmental interactions and endogenous developmental processes facilitating plants to adapt to favorable or adverse soil conditions. Plant root branching is paramount to ensure adequate access to soil water and nutrients. Although substantial resources have been devoted toward this goal, significant knowledge gaps exist. In well-studied systems such as rice and maize, it has become evident that root branching plays a significant role in the acquisition of nutrients and other soil-based resources. In these crop species, specific root branching traits that confer enhanced nutrient acquisition are well-characterized and are already being incorporated into breeding populations. In contrast, the understanding of root branching in root and tuber crop productivity has lagged behind. In this review article, we highlight what is known about root branching in root and tuber crops (RTCs) and mark new research directions, such as the use novel phenotyping methods, examining the changes in root morphology and anatomy under nutrient stress, and germplasm screening with enhanced root architecture for more efficient nutrient capture. These directions will permit a better understanding of the interaction between root branching and nutrient acquisition in these globally important crop species.

Involvement of nitrogen in storage root growth and related gene expression in sweet potato (Ipomoea batatas)

“…Similarly, higher numbers of root stage‐specific genes were found at 30 DAT, which is a major morphological event in storage root formation and bulking (Wang et al ., ). Moreover, P and K also play important roles during storage root formation at the early stage (30–40 DAT) (Wang et al ., ; Duque & Villordon, ). Results of this and previous research suggests that the early growth stage (30–40 DAT) is an important time period for efficient nutrient (N, P, K) use, which regulates storage root formation in sweet potato.…”

“…Research also found that 30–40 DAT (days after transplanting) was an important stage for storage root formation and bulking, even under nutrient stress. Low P can modify root cortical aerenchyma‐like structure formation at 30 DAT (Duque & Villordon, ), while sufficient K (potassium) is beneficial for storage root formation and yield at 40 DAT (Wang et al ., ). Moreover, 30 DAT is a major morphological event when higher numbers of root stage‐specific genes have been observed (Wang et al ., ).…”

“…However, information on the physiological and molecular mechanisms involved in storage root growth and development in sweet potato remains fragmentary. Research into root branching underlying nutrient acquisition in tuber crops is limited (Duque & Villordon, ). In a previous study, genes expressed during the storage root development stage were analysed using microarray hybridization (Wang et al ., ).…”

Multi-copy alpha-amylase genes are crucial for Ditylenchus destructor to parasitize the plant host

“…Over 4100 species of plant-parasitic nematodes are distributed globally and cause huge agricultural losses ($80~173 billion) annually [ 1 – 3 ]. Among them, Ditylenchus destructor Throne, commonly known as potato rot nematode or stem nematode, is one of the primary pathogens in the global production of sweet potato ( Ipomoea batatas ) and potato ( Solanum tuberosum ), the two main root and tuber crops essential for food security [ 4 , 5 ]. In China, the country producing 75% production of world sweet potato, D .…”

The peptidyl-prolyl isomerases FKBP15-1 and FKBP15-2 negatively regulate lateral root development by repressing a vacuolar invertase in Arabidopsis

“…To meet the demands of plant growth and survival, the root system needs to develop a large number of lateral roots to increase root space in the soil [2]. Plants with well-developed lateral root system usually have better nutrient absorption capabilities and higher yields [3].…”