Sorghum (Sorghum bicolor) varieties adopt strongly contrasting strategies in response to drought

Abstract

Sorghum is one of the most drought tolerant crops but surprisingly, little is known about the mechanisms achieving this. We have compared physiological and biochemical responses to drought in two sorghum cultivars with contrasting drought tolerance. These closely related cultivars have starkly contrasting responses to water deficit. In the less tolerant Samsorg 40, drought induced progressive loss of photosynthesis. The more drought tolerant Samsorg 17 maintained photosynthesis, transpiration and chlorophyll content until the most extreme conditions. In Samsorg 40, there was a highly specific down-regulation of selected proteins, with loss of PSII and Rubisco but maintenance of PSI and cytochrome b6 f, allowing plants to maintain ATP synthesis. The nitrogen released allows for accumulation of glycine betaine and proline. To the best of our knowledge, this is the first example of specific reengineering of the photosynthetic apparatus in response to drought. In contrast, in Samsorg 17 we detected no substantial change in the photosynthetic apparatus. Rather, plants showed constitutively high soluble sugar concentration, enabling them to maintain transpiration and photosynthesis, even in extremely dry conditions. The implications for these strikingly contrasted strategies are discussed in relation to agricultural and natural systems.

SWAPDT: A method for Short-time Withering Assessment of Probability for Drought Tolerance in Camellia sinensis validated by targeted metabolomics

“…disrupts plant metabolism resulting in metabolic pathway reconfiguration, ensuring plant survival (Hamanishi et al, 2015). Plants have established innumerable strategies in response to drought (Ogbaga et al, 2014). A common leaf response to drought stress involves both physical and morphological changes.…”

Fourier transform infrared spectroscopic analysis of maize (Zea mays) subjected to progressive drought reveals involvement of lipids, amides and carbohydrates

“…Plant pots were weighed every two days during the period of drought stress until the 12 th day. Soil water content (SWC) was estimated relative to water saturated controls using the formula: (FW-DW)/(AvFW-DW) × 100, where FW is the fresh weight of soil, DW is the dry weight of soil after drying to constant weight at 105°C and AvFW is the average fresh weight of the soils in the pots on day 0 of the experiment (Ogbaga et al, 2014). Twelve groups were used in the experiment for 1 plant x the 12 SWC conditions.…”

“…Fully expanded leaf and shoot tissues from Days 0 to 12 and % soil water contents were excised 8 h into photoperiod with a pair of scissors, flash frozen in liquid nitrogen and lyophilized (freeze dried) with a Scan Vac Coolsafe freeze dryer (Vacuubrand, Wertheim, Germany) for 48 h as described by Ogbaga et al (2016). FTIR spectroscopy was performed on 30 mg of dried homogenized tissues.…”

Phytotoxic analysis of the impact of transmission oil contaminated soil on germination and growth of oat (<i>Avena sativa</i>) seedlings under different soil moisture conditions

“…Comparative analysis of the samples with 60% soil moisture displayed a better outcome in contrast to samples with 30% soil moisture. This suggests that the level of soil moisture at 60% may be optimal for intensifying microbial activity in mitigating the toxic effect of transmission oil (Ogbaga, 2014;.…”