Sensitivity of chickpea and faba bean to root‐zone hypoxia, elevated ethylene, and carbon dioxide

Abstract

During soil waterlogging, plants experience O deficits, elevated ethylene, and high CO in the root-zone. The effects on chickpea (Cicer arietinum L.) and faba bean (Vicia faba L.) of ethylene (2 μL L ), CO (2-20% v/v) or deoxygenated stagnant solution were evaluated. Ethylene and high CO reduced root growth of both species, but O deficiency had the most damaging effect and especially so for chickpea. Chickpea suffered root tip death when in deoxygenated stagnant solution. High CO inhibited root respiration and reduced growth, whereas sugars accumulated in root tips, of both species. Gas-filled porosity of the basal portion of the primary root of faba bean (23%, v/v) was greater than for chickpea (10%), and internal O movement was more prominent in faba bean when in an O -free medium. Ethylene treatment increased the porosity of roots. The damaging effects of low O , such as death of root tips, resulted in poor recovery of root growth upon reaeration. In conclusion, ethylene and high CO partially inhibited root extension in both species, but low O in deoxygenated stagnant solution had the most damaging effect, even causing death of root tips in chickpea, which was more sensitive to the low O condition than faba bean.

Effects of Elevated Root-Zone CO2 on Root Morphology and Nitrogen Metabolism Revealed by Physiological and Transcriptome Analysis in Oriental Melon Seedling Roots

“…The actual CO 2 concentration in the soil also depends on the soil water content, soil type, soil depth, microbial biomass, and the activities of soil microorganisms. Responses to high CO 2 soil environment have received increased attention recently in several crop species [5][6][7][8]. However, little information is available regarding the molecular mechanisms of plants in response to elevated root-zone CO 2 conditions, especially at the transcriptome level.…”

“…In lettuce, high levels of root-zone CO 2 could alleviate the midday depression of photosynthesis and negative impacts of high air temperature on photosynthesis [11], and promoted NO 3 − uptake and the growth of lettuce plants in the greenhouse [12,13]. By contrast, high root-zone soil CO 2 had a negative impact on morphological and physiological indicators, such as plant height, root length, chlorophyll content, photosynthesis rate, stomata conductance, and NO 3 − absorption and assimilation in soybean [14], maize [5], barley [15], and bean [7]. Previous studies have implied that elevated root-zone CO 2 acted as a weak acid, causing acidification in root cells, and inhibition of nutrient uptake and the root respiration rate [16].…”

Changes in gene expression during germination reveal pea genotypes with either “quiescence” or “escape” mechanisms of waterlogging tolerance

“…In pea (Pisum sativum L.), the severity of the effect of waterlogging depends on the growth stage of the plant (Belford, Cannell, Thomson, & Dennis, 1980;Cannell, Gales, Snaydon, & Suhail, 1979). Other legume crops such as chickpea (Cicer arietinum L.; Cowie, Jessop, & MacLeod, 1996;Palta, Ganjeali, Turner, & Siddique, 2010), mungbean (Vigna radiate L.; Islam et al, 2008), and faba bean (Vicia faba L.; Munir, Konnerup, Khan, Siddique, & Colmer, 2018) have also demonstrated diverse responses to waterlogging at different stages of development. Waterlogging is a common problem at the germination stage as pea is often sown as relay with monsoonal rice in Bangladesh (Ali & Sarker, 2013), India, and Nepal.…”

Morpho-physiological responses of chili peppers (Capsicum annuum) to short-term exposure of water-saturated rhizosphere

“…Chili pepper is suspected does not have a specific anatomical feature and metabolisms to overcome oxygen deficit; therefore, its roots are vulnerable to this oxygen-deficient condition. Munir et al (2018) reported that inhibition of root extension was associated with increase of ethylene in roots and high CO2 concentration entrapped within rhizosphere due to slow diffusion of these molecules in water; however, the most damaging effect, even causing death of root tips, was due to O2 deficiency. Short-term or partial exposure to WSR did not set off permanent effect to roots in some plants, as Lakitan et al (2018b) reported that roots were able to regrow after water-saturated condition gradually diminished.…”