Transportation or sharing of stress signals among interconnected ramets improves systemic resistance of clonal networks to water stress

2019 ◽  
Vol 46 (7) ◽  
pp. 613 ◽  
Author(s):  
Qing Wei ◽  
Qian Li ◽  
Yu Jin ◽  
Shulan Wu ◽  
Lihua Fan ◽  
...  

Previous studies have elucidated the mechanisms, ecological implications and constraints on transportation or sharing of defence signals among interconnected ramets of clonal plants suffering from localised herbivore damage. To our knowledge, few studies have been conducted to provide insights into the ecological implications on transportation or sharing of stress signals for clonal plants subjected to water stress. As a chemical elicitor, ABA can induce resistance response in plants suffering from water stress. A pot experiment was conducted to explore transportation or sharing of stress signals among interconnected ramets by using clonal fragments of Centella asiaticas (L.) Urban with four successive ramets (oldest, old, mature and young) subjected to low water availability (20% soil moisture contents). Compared with control, foliar oxidative stress of the old, mature and young ramets significantly decreased, and antioxidant capacity was increased when exogenous ABA was applied to the oldest ramets. Meanwhile, foliar PSII activity and chlorophyll content of the old, mature and young ramets significantly increased. Compared with control, biomass accumulation and ratio of below-ground/aboveground biomass of whole clonal fragments were significantly increased by ABA application to the oldest ramets. However, similar patterns were not observed when exogenous ABA was applied to the young ramets. Our results show that transportation or sharing of stress signals among interconnected ramets improves systemic resistance of clonal networks to water stress, which is dependent on directionality of vascular flows. Compared with the old or mature ramets, the young ramets displayed stronger resistance response (such as higher antioxidant enzymes activities and proline content, lower O2•− production rate and malondialdehyde content) to water stress as well as higher PSII activity and chlorophyll content when exogenous ABA was applied to the oldest ramets. Thus, transportation or sharing of stress signals may favour young ramets that are most valuable for growth and fitness of clonal plant subjected to environmental stress. It is suggested that transportation or sharing of stress signals among interconnected ramets may confer clonal plants with considerable benefits in adapting to spatio-temporal heterogeneous habitats.

Agronomy ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 563
Author(s):  
Esther Anokye ◽  
Samuel T. Lowor ◽  
Jerome A. Dogbatse ◽  
Francis K. Padi

With increasing frequency and intensity of dry spells in the cocoa production zones of West Africa, strategies for mitigating impact of water stress on cocoa seedling survival are urgently required. We investigated the effects of applied potassium on biomass accumulation, physiological processes and survival of cocoa varieties subjected to water stress in pot experiments in a gauzehouse facility. Four levels of potassium (0, 1, 2, or 3 g/plant as muriate of potash) were used. Soil water stress reduced plant biomass accumulation (shoot and roots), relative water content (RWC), chlorophyll content and fluorescence. Leaf phenol and proline contents were increased under water stress. Additionally, compared to the well-watered conditions, soils under water stress treatments had higher contents of exchangeable potassium and available phosphorus at the end of the experimental period. Potassium applied under well-watered conditions reduced leaf chlorophyll content and fluorescence and increased leaf electrolyte leakage, but improved the growth and integrity of physiological functions under soil water stress. Potassium addition increased biomass partitioning to roots, improved RWC and leaf membrane stability, and significantly improved cocoa seedling survival under water stress. Under water stress, the variety with the highest seedling mortality accumulated the highest contents of phenol and proline. A significant effect of variety on plant physiological functions was observed. Generally, varieties with PA 7 parentage had higher biomass partitioning to roots and better seedling survival under soil moisture stress. Proportion of biomass partitioned to roots, RWC, chlorophyll fluorescence and leaf electrolyte leakage appear to be the most reliable indicators of cocoa seedling tolerance to drought.


2020 ◽  
Vol 41 (4) ◽  
pp. 1093
Author(s):  
Suerlani Aparecida Ferreira Moreira ◽  
Pablo Fernando Santos Alves ◽  
Carlos Eduardo Corsato ◽  
Alcinei Mistico Azevedo

Maize hybrids contrasting for drought tolerance differ during the vegetative stage. Drought is the main constraint on maize production in developing nations. Differences during development between genetic materials of maize grown under water restriction suggest that the plant can be improved with a view to its adaptation. In maize, sensitivity to water stress can occur at any stage of its phenological development. However, few studies report its effects on the vegetative phase of the cycle. On this basis, this study was conducted to examine how shoot and root-system indices are expressed in cultivation under water deficit as well as determine which indicators best explain the difference between hybrids in the evaluated water regimes. Commercial seeds of hybrids BR1055 and DKB-390 (drought-tolerant) and BRS1010 (drought-sensitive) were germinated in PVC tubes (1.0 m × 0.1 m) in a randomized complete block design, in a 3 × 2 factorial arrangement. The experiment was developed in a greenhouse where two water regimes were tested: no water stress and with water stress from the VE stage. The soil consisted of quartz sand mixed with a commercial fertilizer. Stem and root traits were evaluated up to the V5 growth stage. Relative chlorophyll content, leaf temperature, stem length, phenology, shoot dry biomass, root length, root dry biomass, root surface area, root volume and D95 were responsive to water deficit. The parameters that allowed the distinction between the hybrids in water the regimes were relative chlorophyll content, leaf temperature, phenology and average root diameter.


Agronomy ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 916
Author(s):  
Innocent Maseko ◽  
Bhekumthetho Ncube ◽  
Samson Tesfay ◽  
Melake Fessehazion ◽  
Albert Thembinkosi Modi ◽  
...  

African leafy vegetables (ALVs) are nutrient dense and can contribute to crop and dietary diversity, especially in water-stressed environments. However, research on their productivity under limited water availability remains scant. The objective of the study was to evaluate growth, physiology and yield responses of three ALVs (Vigna unguiculata, Corchorus. Olitorius and Amaranthus cruentus) and a reference vegetable (Beta vulgaris var. cicla) to varying water regimes [30%, 60% and 100% of crop water requirement (ETc)]. Field trials using a randomised complete block design, replicated three times, were conducted over two summer seasons, 2015/16 and 2016/17. Leaf number, plant height, chlorophyll content index (CCI), chlorophyll fluorescence (CF), and yield were measured in situ. For A. cruentus and C. olitorius, water stress (30% ETc) was shown to produce a lower yield, although leaf number, plant height and chlorophyll content index were unaffected, while for B. vulgaris, leaf number and yield were reduced by water stress. For V. unguiculata, CF, CCI, plant height, leaf number, and yield were not affected by water stress, indicating its suitability for production in water scarce environments. Using 60% ETc was suitable for the production of A. cruentus, C. olitorius and B. vulgaris var. cicla, whereas 30% ETc is recommended for V. unguiculata. The yield results of V. unguiculata indicate that it performs better, while the yield of A. cruentus and C. olitorius is comparable to that of B. vulgaris under similar conditions, indicating potential for marginal production.


Microbiology ◽  
2012 ◽  
Vol 158 (1) ◽  
pp. 139-146 ◽  
Author(s):  
Yariv Brotman ◽  
Jan Lisec ◽  
Michaël Méret ◽  
Ilan Chet ◽  
Lothar Willmitzer ◽  
...  

2019 ◽  
Vol 11 (18) ◽  
pp. 5086 ◽  
Author(s):  
Libing Song ◽  
Jiming Jin ◽  
Jianqiang He

In this study, we investigated the effects of water stress on the growth and yield of summer maize (Zea mays L.) over four phenological stages: Seedling, jointing, heading, and grain-filling. Water stress treatments were applied during each of these four stages in a water-controlled field in the Guanzhong Plain, China between 2013 and 2016. We found that severe water stress during the seedling stage had a greater effect on the growth and development of maize than stress applied during the other three stages. Water stress led to lower leaf area index (LAI) and biomass owing to reduced intercepted photosynthetically active radiation (IPAR) and radiation-use efficiency (RUE). These effects extended to the reproductive stage and eventually reduced the unit kernel weight and yield. In addition, the chlorophyll content in the leaf remained lower, even though irrigation was applied partially or fully after the seedling stage. Severe and prolonged water stress in maize plants during the seedling stage may damage the structure of the photosynthetic membrane, resulting in lower chlorophyll content, and therefore RUE, than those in the plants that did not experience water stress at the seedling stage. Maize plants with such damage did not show a meaningful recovery even when irrigation levels during the rest of the growth period were the same as those applied to the plants not subjected to water stress. The results of our field experiments suggest that an unrecoverable yield loss could occur if summer maize were exposed to severe and extended water stress events during the seedling stage.


2014 ◽  
Vol 27 (6) ◽  
pp. 567-577 ◽  
Author(s):  
Feng Zhu ◽  
De-Hui Xi ◽  
Shu Yuan ◽  
Fei Xu ◽  
Da-Wei Zhang ◽  
...  

Systemic resistance is induced by pathogens and confers protection against a broad range of pathogens. Recent studies have indicated that salicylic acid (SA) derivative methyl salicylate (MeSA) serves as a long-distance phloem-mobile systemic resistance signal in tobacco, Arabidopsis, and potato. However, other experiments indicate that jasmonic acid (JA) is a critical mobile signal. Here, we present evidence suggesting both MeSA and methyl jasmonate (MeJA) are essential for systemic resistance against Tobacco mosaic virus (TMV), possibly acting as the initiating signals for systemic resistance. Foliar application of JA followed by SA triggered the strongest systemic resistance against TMV. Furthermore, we use a virus-induced gene-silencing–based genetics approach to investigate the function of JA and SA biosynthesis or signaling genes in systemic response against TMV infection. Silencing of SA or JA biosynthetic and signaling genes in Nicotiana benthamiana plants increased susceptibility to TMV. Genetic experiments also proved the irreplaceable roles of MeSA and MeJA in systemic resistance response. Systemic resistance was compromised when SA methyl transferase or JA carboxyl methyltransferase, which are required for MeSA and MeJA formation, respectively, were silenced. Moreover, high-performance liquid chromatography–mass spectrometry analysis indicated that JA and MeJA accumulated in phloem exudates of leaves at early stages and SA and MeSA accumulated at later stages, after TMV infection. Our data also indicated that JA and MeJA could regulate MeSA and SA production. Taken together, our results demonstrate that (Me)JA and (Me)SA are required for systemic resistance response against TMV.


HortScience ◽  
1996 ◽  
Vol 31 (4) ◽  
pp. 601d-601
Author(s):  
Chuhe Chen ◽  
J. Scott Cameron ◽  
Stephen F. Klauer

Leaf fluorescence characteristics, chlorophyll (Chl) content and 4th-derivative spectra were measured six times before, during, and after water stress development in F. chiloensis and F. ×ananassa grown in growth chambers. The younger strawberry leaves under water stress maintained higher Chl a, Chl b, and total Chl contents than those under nonstressed conditions, while the older ones lost Chl quickly under water stress and then died. In comparison to F. ×ananassa, F. chiloensis had significantly higher Chl a, Chl b, and total Chl contents and peak amplitudes of Cb 630 and Ca 693 in 4th-derivative spectra under stressed and nonstressed conditions. The differences in peak amplitude of Ca 693 between the two species increased under water stress. Fq was the most sensitive fluorescence characteristic to water stress and was reduced significantly under stress. Fm and Fv decreased significantly under more severe water stress. A reduction in Fv suggests that severe water stress might cause thylakoid damage and photoinhibition in the leaves, which resulted in a very depressed CO2 assimilation level. F. chiloensis had significantly higher Ft and Fq before and under water stress development (but not after stress recovery) than F. ×ananassa.


2024 ◽  
Vol 84 ◽  
Author(s):  
M. Javed ◽  
M. Iqbal ◽  
H. Bano ◽  
N. Hussain ◽  
A. Ghaffar ◽  
...  

Abstract Growth of plants is severely reduced due to water stress by affecting photosynthesis including photosystem II (PSII) activity and electron transport. This study emphasised on comparative and priority targeted changes in PSII activity due to progressive drought in seven populations of Panicum antidotale (P. antidotale) collected from Cholistan Desert and non-Cholistan regions. Tillers of equal growth of seven populations of P. antidotale grown in plastic pots filled with soil were subjected progressive drought by withholding water irrigation for three weeks. Progressive drought reduced the soil moisture content, leaf relative water content, photosynthetic pigments and fresh and dry biomass of shoots in all seven populations. Populations from Dingarh Fort, Dingarh Grassland and Haiderwali had higher growth than those of other populations. Cholistani populations especially in Dingarh Grassland and Haiderwali had greater ability of osmotic adjustment as reflected by osmotic potential and greater accumulation of total soluble proteins. Maximum H2O2 under water stress was observed in populations from Muzaffargarh and Khanewal but these were intermediate in MDA content. Under water stress, populations from Muzaffargarh and Dingarh Fort had greater K+ accumulation in their leaves. During progressive drought, non-Cholistani populations showed complete leaf rolling after 23 days of drought, and these populations could not withstand with more water stress condition while Cholistani populations tolerated more water stress condition for 31 days. Moreover, progressive drought caused PSII damages after 19 days and it became severe after 23 days in non-Cholistani populations of P. antidotale than in Cholistani populations.


Sign in / Sign up

Export Citation Format

Share Document