Functional Plant Biology最新文献

Under salt stress, plants are forced to take up and accumulate large amounts of sodium (Na+ ) and chloride (Cl- ). Although most studies have focused on the toxic effects of Na+ on plants, Cl- stress is also very important. This study aimed to clarify physiological mechanisms underpinning growth contrasts in canola varieties with different salt tolerance. In hydroponic experiments, 150mM Na+ , Cl- and NaCl were applied to salt-tolerant and sensitive canola varieties. Both NaCl and Na+ treatments inhibited seedling growth. NaCl caused the strongest damage to both canola varieties, and stress damage was more severe at high concentrations of Na+ than Cl- . High Cl- promoted the uptake of ions (potassium K+ , calcium Ca2+ ) and induced antioxidant defence. Salt-tolerant varieties were able to mitigate ion toxicity by maintaining lower Na+ content in the root system for a short period of time, and elevating magnesium Mg2+ content, Mg2+ /Na+ ratio, and antioxidant enzyme activity to improve photosynthetic capacity. They subsequently re-established new K+ /Na+ and Ca2+ /Na+ balances to improve their salt tolerance. High concentrations of Cl salts caused less damage to seedlings than NaCl and Na salts, and Cl- also had a positive role in inducing oxidative stress and responsive antioxidant defence in the short term.

Heterosis is a crucial factor in enhancing crop yield, particularly in sorghum (Sorghum bicolor ). This research utilised six sorghum restorer lines, six sorghum sterile lines, and 36 hybrid combinations created through the NCII incomplete double-row hybridisation method. We evaluated the performance of F1 generation hybrids for leaf photosynthesis-related parameters, carbon metabolism-related enzymes, and their correlation with yield traits during the flowering stage. Results showed that hybrid sorghum exhibited significant high-parent heterosis in net photosynthetic rate (P n ), transpiration rate (T r ), stomatal conductance (G s ), apparent leaf meat conductance (AMC), ribulose-1,5-bisphosphate (RuBP) carboxylase, phosphoenolpyruvate (PEP) carboxylase, and sucrose phosphate synthase (SPS). Conversely, inter-cellular carbon dioxide concentration (C i ), instantaneous water uses efficiency (WUE), and sucrose synthase (SuSy) displayed mostly negative heterosis. Traits such as 1000-grain weight (TGW), grain weight per spike (GWPS), and dry matter content (DMC) exhibited significant high-parent heterosis, with TGW reaching the highest value of 82.54%. P n demonstrated positive correlations with T r , C i , G s , RuBP carboxylase, PEP carboxylase, GWPS, TGW, and DMC, suggesting that T r , C i , and G s could aid in identifying high-photosynthesis sorghum varieties. Concurrently, P n could help select carbon-efficient sorghum varieties due to its close relationship with yield. Overall, the F1 generation of sorghum hybrids displayed notable heterosis during anthesis. Combined with field performance, P n at athesis can serve as a valuable indicator for early prediction of the yield potential of the F1 generation of sorghum hybrids and for screening carbon-efficient sorghum varieties.

ERECTA (ER) is a type of receptor-like kinase that contributes a crucial mission in various aspects of plant development, physiological metabolism, and abiotic stresses responses. This study aimed to explore the functional characteristics of the SiER family genes in millet (Setaria italica L.), focusing on the growth phenotype and drought resistance of Arabidopsis overexpressed SiER4_X1 and SiER1_X4 genes (SiERs ). The results revealed that overexpression of SiER4_X1 and SiER1_X4 genes in Arabidopsis significantly enhanced the leaf number, expanded leaf length and width, further promoted the silique number, length and diameter, and plant height and main stem thickness, ultimately leading to a substantial increase in individual plant biomass. Compared to the wild-type (WT), through simulated drought stress, the expression level of SiER genes was notably upregulated, transgenic Arabidopsis seeds exhibited stronger germination rates and root development; after experiencing drought conditions, the activities of antioxidant enzymes (superoxide dismutase and peroxidase) increased, while the levels of malondialdehyde and relative electrical conductivity decreased. These results indicate that overexpression of SiERs significantly enhanced both biomass production and drought resistance in Arabidopsis . The SiER4_X1 and SiER1_X4 genes emerge as promising candidate genes for improving biomass production and drought resistance in forage plants.

Two markers on Chromosome 2 of chickpea (Cicer arietinum ) are reportedly associated with resistance to race 4 Fusarium wilt, and are frequently used in breeding. However, the genes in this region that actually confer wilt resistance are unknown. We aimed to characterise them using both in silico approaches and marker trait association (MTA) analysis. Of the 225 protein-encoding genes in this region, 51 showed significant differential expression in two contrasting chickpea genotypes under wilt, with potential involvement in stress response. From a diverse set of 244 chickpea genotypes, two sets of 40 resistant and 40 susceptible genotypes were selected based on disease incidence and amplification pattern of the TA59 marker. All cultivars were further genotyped with 1238 single nucleotide polymorphisms (SNPs) specific to the 51 genes; only seven SNPs were significantly correlated with disease. SNP Ca2_24099002, specific to the LOC101498008 (Transmembrane protein 87A) gene, accounted for the highest phenotypic variance for disease incidence at 16.30%, whereas SNPs Ca2_25166118 and Ca2_27029215, specific to the LOC101494644 (β-glucosidase BoGH3B-like) and LOC101505289 (Putative tRNA pseudouridine synthase) genes, explained 10.51% and 10.50% of the variation, respectively, in the sets with contrasting disease susceptibility. Together with the TA59 and TR19 markers, these SNPs can be used in a chickpea breeding scheme to develop wilt resistance.

Priming enables plants to respond more promptly, minimise damage, and survive subsequent stress events. Here, we aimed to assess the efficacy of priming and cross-priming in mitigating the stress caused by waterlogging and/or dehydration in soybeans (Glycine max ). Soybean plants were cultivated in a greenhouse in plastic pots in which soil moisture was maintained at pot capacity through irrigation. The first stress was applied in plants at the vegetative stage for 5days and involved either dehydration or waterlogging, depending on the treatment. Subsequently, the plants were irrigated or drained and maintained at pot capacity until the second stress. For the second stress, the conditions were repeated in plants at the reproductive stage. We then evaluated the levels of hydrogen peroxide (H2 O2 ), lipid peroxidation, total soluble sugars (TSS), amino acids, proline, and starch, and the activity of antioxidant, fermentative, and aminotransferase enzymes. Under waterlogging and dehydration, priming and cross-priming significantly increased the activity of antioxidant enzymes and the levels of TSS, amino acids, and proline while reducing H2 O2 concentration and lipid peroxidation. Under waterlogging, priming suppressed fermentative activity and increased carbohydrate content. This demonstrates that soybean plants activate their defence systems more promptly when subjected to priming.

Chilli (Capsicum annuum ) is an important spice crop in Bangladesh. This crop is very sensitive to waterlogging. Floating agriculture is an innovative system led by the local people of the southern region of Bangladesh, in which seedlings of vegetables are produced in low-lying areas using different aquatic macrophytes. An experiment was carried out to evaluate the viability of chilli cultivation in waterlogged areas, based on physiological and biochemical responses using floating agriculture. Eight different chilli varieties were subjected to floating agriculture in two different agronomic seasons. A soil-based chilli cultivation system was also trialled, to compare the utility of this method. To evaluate the performance of chilli in floating beds, plant water status, photosynthetic parameters, and leaf tissue concentrations of Na+ , K+ , NO3 - and PO4 3- , chlorophyll, ascorbic acid and proline were assessed. This study shows that macrophytes utilised in floating beds provide favourable conditions for chilli cultivation under waterlogged conditions. Among the different varieties, Sakata 653 in summer and Jhilik in winter responded better than others. As the performance of chilli in the floating agriculture system was satisfactory in comparison with soil-based cultivation, floating agriculture can be an alternative agronomic method for chilli cultivation in waterlogged areas of Bangladesh.

CONSTANS-LIKE (COL ) genes are a key signalling molecule that regulates plant growth and development during the photoperiod. Our preliminary experiments showed that the photoperiod greatly influence the formation of Tetrastigma hemsleyanum root tubers. In this study, we examined the oscillation patterns and expression characteristics of COL genes in leaves of T. hemsleyanum under different photoperiod conditions. Six genes were selected as candidate reference genes for further analyses: (1) 18S ribosomal RNA (18S rRNA ); (2) α-tubulin (TUBA ); (3) 30S ribosomal RNA (30S rRNA ); (4) TATA binding protein (TBP ); (5) elongation factor 1α (EF-1α ); and (6) RNA polymerase II (RPII ). The geNorm, NormFinder, and BestKeeper software programs were used to evaluate expression stability. Two ThCOL genes were screened in the T. hemsleyanum transcriptome library, and their expression patterns under different photoperiod conditions were analysed using quantitative reverse transcription PCR. The genes EF-1α , TUBA , and 18S rRNA were used to analyse the expression profiles of CONSTANS genes (ThCOL4 and ThCOL5 ) under different photoperiods. The expression peaks of ThCOL4 and ThCOL5 appeared at different times, demonstrating that their oscillation patterns were influenced by the photoperiod. We speculate that these two ThCOL genes may be involved in different biological processes.

Abscisic acid (ABA) regulates plant development, seed germination, and stress responses. The PYR1-like (PYL) proteins are essential for ABA signalling. However, the evolution and expression of PYL genes in potato (Solanum tuberosum ) remain poorly understood. Here, we analysed and identified 17 PYL genes in the potato genome, which were categorised into three groups based on phylogenetic analysis. These genes are distributed across nine chromosomes with predicted proteins subcellar localisation primarily in the cytoplasm. These StPYLs revealed conserved exon structures and domains among the groups. Promoter region analysis indicated hormone and stress-related elements in all StPYL s. Protein-protein interactions and microRNA networks predicted that the interactions of StPYLs are crucial components of ABA signalling, underlining their pivotal role in stress management and growth regulation in potato. Expression profiling across different tissues and under various stresses revealed their varied expression pattern. Further, we validated the expression pattern of selected StPYLs through reverse transcription quantitative PCR under drought, salt, and Phytophthora infestans stresses. This revealed consistent upregulation of StPYL6 in these stresses, while StPYL11 exhibited significant downregulation over time. Other genes showed downregulation under drought and salt stresses while upregulation under P. infestans . Overall, our results suggested the potential role of PYL genes in abiotic and biotic stresses.

One strategy to improve olive (Olea europaea ) tree drought tolerance is through the symbiosis of arbuscular mycorrhizal fungi (AMF), which helps alleviate water deficit through a combination of morphophysiological effects. Cuttings of olive varieties Arbequina (A) and Barnea (B) were grown with (+AMF) or without (-AMF) inoculum in the olive grove rhizosphere soil. One year after establishment, pots were exposed to four different water regimes: (1) control (100% of crop evapotranspiration); (2) short-period drought (20days); (3) long-period drought (25days); and (4) rewatering (R). To evaluate the influence of AMF on tolerance to water stress, stem water potential, stomatal conductance and the biomarkers for water deficit malondialdehyde, proline, soluble sugars, phenols, and flavonoids were evaluated at the end of the irrigation regimes. Stem water potential showed higher values in A(+) and B(+) in all water conditions, and the opposite was true for stomatal conductance. For proline and soluble sugars, the stem water potential trend is repeated with some exceptions. AMF inoculum spore communities from A(+ and -) and B(+ and -) were characterised at the morphospecies level in terms of richness and abundance. Certain morphospecies were identified as potential drought indicators. These results highlight that the benefits of symbiotic relationships between olive and native AMF can help to mitigate the effects of abiotic stress in soils affected by drought.

The WUSCHEL-related homeobox (WOX) transcription factor family plays critical roles in plant growth, development, and stress adaptation, but the biological functions in response to various stress of the WOX gene family have not been extensively researched in grapevine (Vitis vinifera ). In this study, 12 grapevine WOXs were identified from the grapevine genome. Quantitative PCR and microarray expression profiling found that the expression of WOXs had an obvious tissue-specific pattern. Conjoint analysis between various tissues and treated materials indicated VvWUS1 expression is associated with expression of genes from grapevine rupestris stem pitting-associated virus; and VvWOX3 with grapevine fanleaf virus. The gene expression patterns of the WOXs in grape were different under salt stress, with VvWOX8/9 , VvWUS1 , and VvWOX3 responding more strongly to salt stress than control by 18.20-, 9.50-, and 9.19-fold. This study further improves understanding of the evolution and function of the WOX gene family, and offers a theoretical framework and reference for breeding grapevine to better tolerate adversity and permit cultivation of seedlings free of viruses.