Acta Physiologiae Plantarum

Zhang, Y.; Guo, W.; Li, X.; Luo, F.; Mo, J.; Feng, S.

doi: 10.1007/s11738-018-2662-3pmid: N/A

Cluster-flowering camellias are among the most promising types of camellia due to both their ornamental characteristics and their resistance capacity, especially to heat and alkaline soils. Because of global climate change, researchers at the Shanghai Botanical Garden are attempting to identify more heat tolerant plants; camellia is such a plant, and it has been promoted for more than 20 years. Morphological and physiological approaches were used in this study to evaluate the heat tolerance of two new cultivars, and new methods were also explored. The results indicate that the heat tolerance of the new cultivar Camellia hybrid ‘Pink Cascade’ is higher than that of Camellia hybrid ‘Sweet Gem’. In addition, infrared thermography can further be used to evaluate the heat resistance of plants in combination with their stomatal and photosynthetic characteristics.

Kępczyński, Jan

doi: 10.1007/s11738-018-2663-2pmid: N/A

Plant-derived smoke, its water extract—the smoke water (SW), and karrikin (KAR1) present in the smoke stimulate seed germination in plants from fire-prone and fire-free areas, including weeds and cultivated plants. There are also plants, the seeds of which can respond only to smoke, but not to KAR1, and vice versa. Smoke and/or KAR1 can be applied in horticulture, agriculture, and revegetation. This review describes effects of smoke and KAR1 on weed seed germination and focuses mainly on the recent knowledge about the physiological role of these factors in dormancy release and germination of Avena fatua caryopses. The involvement of gibberellins, ethylene, and abscisic acid (ABA) in the response to smoke or KAR1 is discussed. Effects of smoke or KAR1 on the contents of reactive oxygen species (ROS), non-enzymatic antioxidants, and activity of the enzymes participating in ROS removal are presented. Cell cycle activity in the response to SW and KAR1 is also considered. Effects of KAR1 on thermodormancy release in A. fatua caryopses are highlighted, as well.

Hu, Wei; Yang, Jiashuo; Wang, Shanshan; Chen, Binglin; Zhou, Zhiguo

doi: 10.1007/s11738-018-2674-zpmid: N/A

Although effects of potassium (K) on cotton growth have been explored extensively, the effects of K deficiency on the physiological changes closely related to cotton fiber development are lacking. Thus, a 2-year field experiment was conducted with two cotton cultivars (Simian 3 and Siza 3) under 0 kg K2O ha−1 (K deficiency) and 300 kg K2O ha−1 (K sufficiency). The results showed that tonoplast adenosine triphosphatase (V-ATPase), pyrophosphatase (PPase), plasma membrane H+-ATPase (PM H+-ATPase), phosphoenolpyruvate carboxylase (PEPC), sucrose synthesis (SuSy) and vacuolar invertase (V-INV) were highly sensitive to K deficiency. The decreases in those enzymes resulted in low malate and soluble sugar contents, which together with low K concentration declined the driving force for fiber elongation, leading to significantly lower fiber length in the 0 kg K2O ha−1 treatment. The activity of sucrose phosphate synthase (SPS) was obviously increased by K deficiency before 20 days post anthesis (DPA), which could partly explain the acceleration of fiber cellulose synthesis and the increase in fiber strength in the 0 kg K2O ha−1 treatment in the early stage. However, SPS activity was decreased by K deficiency after 20 DPA and SuSy activity was reduced by K deficiency at any sampling date, resulting in low fiber strength in the end. Compared with Simian 3, the enzymes V-ATPase, PPase, PM H+-ATPase, PEPC and SuSy during fiber elongation stage were more sensitive to K deficiency in Siza 3, and the enzymes SuSy and SPS during fiber-thickening stage were more sensitive to K deficiency in Siza 3, which were the important reasons causing greater decreases in final fiber length and final fiber strength for Siza 3 than Simian 3 under K deficiency.

Warchoł, Marzena; Czyczyło-Mysza, Ilona; Marcińska, Izabela; Dziurka, Kinga; Noga, Angelika; Skrzypek, Edyta

doi: 10.1007/s11738-018-2669-9pmid: N/A

Doubled haploid (DH) technology in oat has not reached the same stage as in other cereals leading to its application in plant breeding. The objective of this investigation was to increase the effectiveness of Avena sativa L. haploid embryo germination obtained by the distant crosses with maize. Developed embryos (obtained from 22 genotypes) were transferred on five germination media: MS (Murashige and Skoog, Physiol Plant 15:473–497, 1962) with 3% sucrose, pH 5.8 (control medium), and 190-2 supplemented with 6 and 9% maltose. The pH of 190-2 was adjusted to 5.5 and 6.0. Of all tested genotypes, 591 haploid embryos were obtained, almost half of them (279) germinated. The rate of haploid embryo germination induced on 190-2 was 6.92%, while in MS it was 3.25%. The sugar and its concentration significantly affected the germination of haploid embryos. The highest percentage of haploid embryo germination (9.11%) and DH lines production (1.64%) was achieved on 190-2 with 9% maltose and pH 6.0. All DH lines are incorporated to breeding programs for the development of new cultivars.

Akrami, Mahmoud; Arzani, Ahmad

doi: 10.1007/s11738-018-2657-0pmid: N/A

This study was aimed to assess physiological responses of melon (Cucumis melo L.) cultivars to salinity stress under field conditions. Seventeen melon cultivars including 16 widely distributed native and one exotic (‘Galia’) were subjected to 2-year (2014–2015) field salinity stress. Leaf relative water content (RWC), membrane stability index (MSI), pigments [chlorophyll a, b, total chlorophyll (TChl), carotenoid (Car) and their ratios], malondialdehyde (MDA), H2O2 content, proline content (Pro), total soluble sugar content (TSC), salinity tolerance and susceptibility indices as well as yield were evaluated. The results of combined analysis of variance showed significant genotypic variation for all the traits and significant effect of salinity stress on all the traits with the exception of Chla/Chlb and TChl/Car ratios. Overall, field salinity stress caused an increase in leaf MDA, H2O2, Chla, Chlb, TChl, Car, Pro and TSC and caused a reduction in leaf MSI and RWC as well as yield. The results of correlation coefficients showed that accumulation of osmolytes (proline and TSC) led to an increase in RWC and a decrease in MDA contents. In addition, the results of multiple regression analysis showed that leaf MDA, TSC, MSI and Chla contents were the most important predictors of yield justifying 72% total variation of yield under saline conditions. These results may highlight a dynamic interplay among biomarkers for lipid peroxidation (MDA), sugar osmolytes (TSC) and photosynthetic pigment (Chla) to maintain cell viability and cell wall integrity under salinity stress conditions in melon.

Singh, Aditya; Chaurasia, Meenakshi; Gupta, Vaishali; Agrawal, Madhoolika; Agrawal, S.

doi: 10.1007/s11738-018-2666-zpmid: N/A

Increase in surface level of ozone (O3) in last 30 years is one of the major problems for global agriculture. Field experiment was conducted using open top chambers on two Indian maize cultivars (Buland and Prakash) grown under ambient (AO) and elevated (EO) O3 concentrations to evaluate the effect of an antiozonant ethylene diurea (EDU) given as soil drench. EDU application reduced the ROS production with concomitant decrease in lipid peroxidation. Inductions in activities of enzymatic antioxidants along with increased content of non-enzymatic antioxidants were observed in EDU-treated plants, though the response varied between the cultivars. Photosynthetic proteins (PEP carboxylase and RuBisCO large and small subunits) detected through SDS–PAGE analysis increased with EDU treatment. EDU also led to an increase in jasmonic acid and a decline in salicylic acid contents. The protective effect of EDU was further accompanied by increased pigments (chlorophyll and carotenoids), foliar carbohydrates (starch and total soluble sugars), enhanced biomass, and economic yield. Effectiveness of EDU was more evident at higher O3 concentration and cultivar Prakash exhibited a more positive response with EDU as compared to Buland.

Chen, Aiguo; Gu, Li; Li, Mingjie; Xu, Na; Feng, Fajie; Liu, Guangliang; Zhang, Bao; Gong, Daping; Zhang, Junyi; Liu, Hongyan; Zhang, Zhongyi

doi: 10.1007/s11738-018-2672-1pmid: N/A

NB-ARC proteins are critical to effector-triggered immunity and play important roles in effector recognition and signal transduction in healthy plant growth. However, their primary protein traits, functions and roles remain incompletely understood in Rehmannia glutinosa. Here, we identified 45 NB-ARC protein sequences from the protein sequence sets and transcriptome of R. glutinosa. The CC type was the main one, accounting for 84.44% of these sequences. The most conserved motif was a 288 aa ADP-binding sequence. This motif belongs to the disease-resistance proteins. Differential expression of 36 expressed NB-ARC genes revealed that NB-ARC genes were rarely expressed 30 days after planting and were frequently expressed approximately 60 days after planting. To further understand the function of NB-ARC in replanted R. glutinosa, the genes encoding NB-ARC domains were profiled using qRT-PCR under the different stress states involved in the formation of consecutive monoculture problems. The results showed that NB-ARC genes might play a role in the formation of R. glutinosa consecutive monoculture problems. This study is the first to identify NB-ARC genes in R. glutinosa and to reveal their roles in consecutive monoculture problems in R. glutinosa. These findings provide insights into the mechanism of formation of consecutive monoculture problems.

Ouledali, Sarra; Ennajeh, Mustapha; Zrig, Ahlem; Gianinazzi, Silvio; Khemira, Habib

doi: 10.1007/s11738-018-2656-1pmid: N/A

The aim of the present study is to investigate the contribution of mycorrhization to the resilience of olive trees to drought. One-year-old olive plants were inoculated (Myc+) or not (Myc−) with arbuscular mycorrhizal fungi (AMF), and subjected to a 40-day-drought period. At regular intervals of the watering-off period and after rehydration period, water relations and gas exchanges parameters were measured. Similarly, the total soluble sugars, proline, and mineral nutrients concentrations were determined. The results revealed that Myc+ plants were less affected by drought than Myc− plants proving the involvement of the AMF in the alleviation of drought impact on olive tree. In fact, the turgor potential (Ψ p) in Myc+ plants exhibited positive values during the whole treatment period, while Ψ p in Myc− plants was negative mainly under severe stress intensity. Moreover, the stomatal function of Myc+ plants was less affected by drought compared to Myc− plants. The maximum of mycorrhizas relative drought alleviation rate (RDAR) was estimated to be 40% for Ψ pd and RWC, 36% for the osmotic potential (Ψ S), 86% for Ψ p, 16% for g s, and 27% for E. The osmotic adjustment by proline was earlier in Myc+ plants than in Myc− ones. The inoculation with AMF also improved mineral uptake (K, N, Zn, and Fe). After 40 days of drought, Myc+ plants survive but not Myc− ones. In addition, the restoration of the irrigation permitted the Myc+ plants to recuperate from severe drought stress. To sum up, inoculation of young olive trees with the AMF improved their resilience to drought.

Ahmadi, Jafar; Pour-Aboughadareh, Alireza; Ourang, Sedigheh; Mehrabi, Ali; Siddique, Kadambot

doi: 10.1007/s11738-018-2673-0pmid: N/A

Wild relatives of wheat are an outstanding source of resistance to both abiotic and biotic stresses. In the present study, we evaluated the activity of four antioxidant enzymes—superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and guaiacol peroxidase (GPX)—along with photosynthetic pigments and shoot biomass in 12 Aegilops–Triticum accessions with different genomic constitutions and two tolerant and sensitive control varieties under well-watered (WW; 90% FC), moderate (MS; 50% FC) and severe (SS; 25% FC) water stress treatments. The analysis of variance for measured traits indicated highly significant effects of the water stress treatments, accessions, and their interactions. The 12 domesticated and wild relatives of wheat exhibited more variability and greater activity in the expression of antioxidative enzymes than cultivated wheats. While domesticated forms of wheat, T. aestivum (AABBDD) and T. durum (AABB) seem to have a functionally active antioxidant mechanism, other accessions with alien genomes—Ae. umbellulata (UU), Ae. crassa (MMDD), Ae. caudata (CC), Ae. cylindrica (DDCC) and T. boeoticum (AbAb)—respond to water stress by increasing enzymatic antioxidants as the dominant mechanism that contributes to the retention of oxidative balance in the cell. Furthermore, abovementioned accessions with alien genomes had higher photosynthetic pigment contents (chlorophyll a, chlorophyll b, total chlorophyll, and carotenoid) under water stress than well-watered conditions. Hence, these accessions could be used in future breeding programs to combine beneficial stress-adaptive characters of alien genomes into synthetic hexaploid wheat varieties in the field, even at limited water supply.

Li, Long; Shi, Qianqian; Hou, Dan; Cheng, Zhanchao; Li, Juan; Ma, Yanjun; Li, Xueping; Mu, Shaohua; Gao, Jian

doi: 10.1007/s11738-018-2661-4pmid: N/A

Alternative splicing (AS) is a key regulatory mechanism associated with proteome and transcriptome diversity. However, the prevalence of AS in the moso bamboo genome is still unclear. Transcriptome sequencing of four different tissues indicated that 36.17% of the genes in the moso bamboo genome undergo AS. The predominant type of AS found in moso bamboo was intron retention (38.70%), followed by alternative 5′ (31.86%) and 3′ (16.68%) splice sites and exon skipping (11.46%). The number of AS events in every gene was relevant to gene characteristics and gene expression. We also observed that the alternative 5′ and 3′ splice sites were significantly enriched in the fourth nucleotide downstream or upstream of the dominant splice sites. Furthermore, the frequency of AS types as well as the quantity of AS events significantly varied among different tissues. The findings of the present study provide a comprehensive view of AS events in moso bamboo.