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Three Cenchrus species (C. biflorus, C. ciliaris, and C. orientalis) were collected from different ecological regions in the Punjab and Khyber Pakhtoonkhwa during July to September 2020 to evaluate tolerance to multiple abiotic stresses (aridity, salinity, and cold). Growth and biomass production was the maximum in C. biflorus, C. ciliaris, and C. orientalis under aridity stress. Aerenchyma formation and vascular tissue increased significantly in roots under aridity. In C. ciliaris, aerenchyma formation was recorded under cold stress. Root vascular tissue was higher under normal conditions (26.7%) and aridity (30.4%) stress in C. ciliaris. Stem parenchyma (29.1%) and vascular tissues (35.5%) showed an increase in C. biflorus under aridity, while mechanical tissue (33.6%) increased significantly under salinity stress. In C. biflorus and C. ciliaris, extensive sclerification was recorded in the stelar region under aridity stress. The stem radius of C. orientalis was greatest under salinity (27.0%) and cold (29.1%) stress, while parenchyma tissue was smaller (12.1%) under cold stress. Leaf thickness generally increased under abiotic stresses, and the maximum (43.0%) thickness was recorded in C. biflorus under aridity stress. Cenchrus biflorus, C. ciliaris, and C. orientalis showed strong association among morphological and leaf anatomical traits under aridity stress. Cenchrus orientalis showed high sclerification outside the vascular bundles of the leaf sheath. In saline conditions, vascular bundles were sclerified and enlarged. In and outside the vascular bundles of leaf blades, extensive sclerification was observed under cold stress conditions. Modifications in structural and functional traits were critical for the ecological success of Cenchrus species for survival in multiple environmental stresses. [ABSTRACT FROM AUTHOR]

Salt excretory halophytes are the major sources of phytoremediation of salt-affected soils. Cressa cretica is a widely distributed halophyte in hypersaline lands in the Cholistan Desert. Therefore, identification of key physio-anatomical traits related to phytoremediation in differently adapted C. cretica populations was focused on. Four naturally adapted ecotypes of non-succulent halophyte Cressa cretica L. form hyper-arid and saline desert Cholistan. The selected ecotypes were: Derawar Fort (DWF, ECe 20.8 dS m−1) from least saline site, Traway Wala Toba (TWT, ECe 33.2 dS m−1) and Bailah Wala Dahar (BWD, ECe 45.4 dS m−1) ecotypes were from moderately saline sites, and Pati Sir (PAS, ECe 52.4 dS m−1) was collected from the highly saline site. The natural population of this species was collected and carefully brought to the laboratory for different structural and functional traits. As a result of high salinity, Na+, Cl–, K+, and Ca2+ content significantly increased at root and shoot level. At root level, some distinctive modifications such as increased sclerification in vascular bundles, enlarged vascular bundles, metaxylem vessels, phloem region, and storage parenchyma (cortex) are pivotal for water storage under extreme arid and osmotic condition. At the stem level, enhanced sclerification in outer cortex and vascular bundles, stem cellular area, cortical proportion, metaxylem and phloem area, and at the leaf level, very prominent structural adaptations were thicker and smaller leaves with increased density of salt glands and trichomes at surface, few and large stomata, reduced cortical and mesophyll parenchyma, and narrow xylem vessels and phloem area represent their non-succulent nature. The ecotype collected from hypersaline environments was better adapted regarding growth traits, ion uptake and excretion, succulence, and phytoremediation traits. More importantly, structural and functional traits such as root length and biomass, accumulation of toxic ions along with K+ in root and shoot, accumulation of Ca2+ in shoot and Mg2+ in root, excretion of toxic ions were the highest in this ecotype. In conclusion, all these alterations strongly favor water conservation, which certainly contributes to ecotypes survival under salt-induced physiological drought. Naturally adapted salt tolerant plants provide exceptional material for exploring adaptive mechanisms they use to confront high salt concentrations. Cressa cretica is a hypersaline hyperarid desert colonizer, which was previously underexplored. In the present study, we focused on the new insight on relationship among anatomical modifications, salt accumulation and excretion and phytoremediation potential of this rare species. [ABSTRACT FROM AUTHOR]

Brassica napus is an important oil crop and cold stress severely limits its productivity. To date, several studies have reported the regulatory genes and pathways involved in cold‐stress responses in B. napus. However, transcriptome‐scale identification of the regulatory genes is still lacking. In this study, we performed comparative transcriptome analysis of cold‐tolerant C18 (CT – C18) and cold‐sensitive C6 (CS – C6) Brassica napus genotypes under cold stress for 7 days, with the primary purpose of identifying cold‐responsive transcription in B. napus. A total of 6061 TFs belonging to 58 families were annotated in the B. napus genome, of which 3870 were expressed under cold stress in both genotypes. Among these, 451 TFs were differentially expressed (DE), with 21 TF genes expressed in both genotypes. Most TF members of the MYB (26), bHLH (23), and NAC (17) families were significantly expressed in the CT – C18 genotype compared with the CS – C6 B. napus genotype. GO classification showed a significant role in transcription regulation, DNA‐binding transcription factor activity, response to chitin, and the ethylene‐activated signaling pathway. KEGG pathway annotation revealed these TFs are involved in regulating more pathways, resulting in more tolerance. In conclusion, the results provide insights into the molecular regulation mechanisms of B. napus in response to freezing treatment, expanding our understanding of the complex molecular mechanisms in plants' response to freezing stress. [ABSTRACT FROM AUTHOR]

Plant performance is mainly estimated based on plant architecture, leaf features and internal microstructural changes. Olive (Olea europaea L.) is a drought tolerant, oil yielding, and medium sized woody tree that shows specific structural and functional modifications under changing environment. This study was aimed to know the microstructural alteration involving in growth and yield responses of different Olive cultivars. Eleven cultivars were collected all over the world and were planted at Olive germplasm unit, Barani Agricultural Research Institute, Chakwal (Punjab) Pakistan, during September to November 2017. Plant material was collected to correlate morpho-anatomical traits with yield contributing characteristics. Overall, the studied morphological characters, yield and yield parameters, and root, stem and leaf anatomical features varied highly significantly in all olive cultivars. The most promising cultivar regarding yield was Erlik, in which plant height seed weight and root anatomical characteristics, i.e., epidermal thickness and phloem thickness, stem features like collenchymatous thickness, phloem thickness and metaxylem vessel diameter, and leaf traits like midrib thickness, palisade cell thickness a phloem thickness were the maximum. The second best Hamdi showed the maximum plant height, fruit length, weight and diameter and seed length and weight. It also showed maximum stem phloem thickness, midrib and lamina thicknesses, palisade cell thickness. Fruit yield in the studied olive cultivars can be more closely linked to high proportion of storage parenchyma, broader xylem vessels and phloem proportion, dermal tissue, and high proportion of collenchyma. [ABSTRACT FROM AUTHOR]

Context: Allelopathy is recognised as a potential technology to control weeds, and could also be a suitable approach for enhancement of crop yield. Aims: The study was conducted to investigate the allelopathic role of Averrhoa carambola leaf extract on growth, anatomical and physiological features of three wheat lines, namely 3094, 7076 and A2011. Methods: Three dilutions i.e. 0% (control), 15% and 30% of the leaf aqueous extract were applied at 15 day intervals (total five applications) on wheat lines until maturity. Key results: All wheat lines showed differential behaviour to allelochemicals of A. carambola leaf extract. Increased root area was accompanied by a high proportion of storage parenchyma tissues and enlarged vascular bundles in line 3094. Disintegration of root cortical parenchyma and complete transformation of chlorenchyma into sclerenchyma in stem was recorded in all wheat lines, particularly at the highest concentration of leaf extract. Line 7076 showed very different behaviour, as it possessed a proportionally enlarged root cortex, enlarged stem vascular bundles and increased leaf thickness, primarily at the highest concentration of leaf extract. Line A2011 was relatively more sensitive, indicating a significant reduction (P < 0.05) in root and stem area and deformed leaves. Conclusions: A low concentration (15%) of leaf extract promoted growth and development, whereas a higher concentration caused significant reduction in growth and anatomical attributes. Implications: A lower dose of Averrhoa leaf extract promoted growth and development in all wheat lines, and hence can be used as a growth promoter. A higher concentration is important for eradicating unwanted plants. Wheat lines were treated with allelochemicals extracted from A. carambola. A low treatment concentration led to increased root area, accompanied by a high proportion of storage parenchyma tissues, and enlarged vascular bundles. Using a high extract concentration, root cortical parenchyma collapsed while stem chlorenchyma was transformed to sclerenchyma. Line 7076 responded differently, as it possessed an enlarged root cortical proportion, enlarged stem vascular bundles and increased leaf thickness. A low concentration (15%) of leaf extract promoted growth, whereas a higher concentration (30%) caused significant reduction in morpho-anatomical traits. [ABSTRACT FROM AUTHOR]

Two ecotypes of Cenchrus setigerus Vahl (birdwood grass) were collected from dry mountains surrounding hyper-saline Kalar Kahar Lake and Gatwala artificial forest plantation. The ramets of the two ecotypes were established in pots for 15 days and then subjected to 100% FC (control) or 75% and 50% FC (field capacity) levels. Growth attributes such as plant height, tillers per plant, leaves per plant, shoot fresh and dry weights were severely affected while root length was the only attribute that increased in both ecotypes under moisture stress. Root anatomical attributes like cortical and pith parenchyma, and vascular region thickness increased in both ecotypes under water stress. Root radius increased in the Faisalabad ecotype at 75% FC, while increased in Salt Range ecotype only at 50% FC. Stem cellular region, sclerenchymatous cell area, vascular bundle area and metaxylem area increased significantly under moderate and severe water deficit only in the Faisalabad ecotype. The Salt Range ecotype exhibited intensive sclerification and large vascular tissue at 50% FC. Leaf anatomical attributes like epidermal cell area, bundle sheath thickness, sclerenchyma thickness and its cell area, and, vascular bundles area significantly increased in the Salt Range ecotype with increasing water deficit. The Faisalabad ecotype showed significant increase in vascular bundle area, metaxylem area and adaxial stomatal area. These findings indicated that both C. setigerus ecotypes mainly relied on water conservation and survival rather than maintaining growth and biomass production. The anatomical modifications at root, stem and leaf levels ensured survival of C. setigerus ecotypes in extreme arid conditions. • Growth attributes were severely affected while root length increased under stress • Root radius increased in the Faisalabad ecotype at 75% FC, while at 50% FC in Salt Range ecotype • Stem area, sclerification and vascular bundle area increased only in Faisalabad ecotype • The Salt Range ecotype exhibited intensive sclerification in leaves and large vascular tissue at 50% FC • The Faisalabad ecotype showed an increase in vascular bundle area, metaxylem area and adaxial stomatal area [ABSTRACT FROM AUTHOR]