Alleviating the adverse effects of deficit irrigation in Flame seedless grapevine via Paulsen interstock

Using interstock with a potential genetic base is considered more recent and sustainable strategy for mitigating the water deficit. This investigation was carried out on transplant of Flame seedless (Vitis vinifera) grapevine grafted onto two rootstocks namely; Freedom (Vitis champinii x 1613C) and 1103Paulsen (vitis berlandieri x Vitis rupestris) with or without 1103Paulsen as interstock to determine its performance under deficit irrigation condition (50% of field capacity). The results indicated that Paulsen as rootstock or as interstock significantly increased the growth vigor of Flame seedless scion as well as the leaf content of total proline, phenols and sugars. Paulsen rootstock has decreased stomatal conductance, leaf transpiration rate and increased diffusion resistance under 50% deficit irrigation compared with grafting on Freedom rootstock. Moreover, Paulsen as interstock for Flame seedless grafted onto Freedom rootstock significantly increased relative water content accompanied by an increase in thickness of leaf anatomical characters such as midvein, lamina, palisade, xylem and phloem tissue under deficit irrigation compared with grafts without Paulsen interstock. This study suggests that using Paulsen as interstock, can be an adaptation strategy for water stress through controlling in some morphological, chemical physiological and anatomical responses of scion.

Understanding the long-term storage sink.

Similar to short-term starch storage in the chloroplasts of the leaves that serves to buffer growth of organs from carbohydrate shortages due to diurnal patterns of photosynthesis related to daily patterns of light and darkness, trees also have long-term storage capacity to enable them to supply the minimal respiratory needs of tissues during the winter and resume growth in the spring when trees are still leafless. This long-term storage of carbohydrates and some minerals occurs primarily in the phloem and xylem tissue of the branches, trunk and roots. While active phloem tissue has higher concentrations of stored carbohydrates than xylem tissue, the mass of active xylem storage tissue is many times the mass of the active phloem tissue. Thus, xylem tissue comprises the largest storage compartment of temperate deciduous fruit trees. This chapter deals with understanding the long-term storage sink in fruit trees.

Cellular and Metabolite Changes in the Secondary Phloem of Chinese Fir (Cuninghamia lanceolata (Lamb.) Hook.) during Dormancy Release

Wood in the cold temperate zone is the product of the alternation of the growing season and the dormant period of trees, but our knowledge of the process of dormancy release in trees remains limited. Chinese fir (Cuninghamia lanceolata (Lamb.) Hook.) was used to investigate cellular and metabolite changes in the secondary phloem tissue during dormancy release. The sampling dates were 2 March, 28 March, and 13 April. The microsections of wood-forming tissue were prepared using the paraffin embedding technique to observe the formation of cambium cells; metabolites in secondary phloem cells were extracted using a methanol/chloroform organic solvent system. The results showed that the secondary phloem consists of phloem fibers, sieve cells and phloem parenchyma. The cells were regularly arranged in continuous tangential bands and were in the order of Phloem fiber-Sieve cell-Phloem parenchyma-Sieve cell-Phloem parenchyma-Sieve cell-Phloem parenchyma-Sieve cell-Sieve cell-Phloem parenchyma-. The Chinese fir cambium was in dormancy on 2 March and 28 March, while on 13 April, it was already in the active stage and two layers of xylem cells with several layers of phloem cells were newly formed. The width of the cambium zone increased from 18.7 ± 5.7 μm to 76.5 ± 3.0 μm and the average radial diameter of sieve cells expanded from 15.4 ± 7.5 μm to 21.5 ± 7.4 μm after dormancy release. The cambium zone width and the average radial diameter of sieve cells before and after dormancy release were significantly different (p < 0.01). The phloem parenchyma cells without resin were squeezed and deformed by the sieve cells, and the width of the phloem during the active period was 197.0 ± 8.5 μm, which was larger than that during the dormant period. Ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)-based metabolomics was employed to analyze the secondary phloem of Chinese fir on 28 March and 13 April. Thirty-nine differential metabolites during dormancy release were detected. The results showed that the composition of Chinese fir metabolites was different before and after dormancy release. The relative increase in pyruvic acid and ascorbic acid contents proved that the rate of energy metabolism in Chinese fir increased substantially after dormancy release. Changes in cell development and the composition of metabolites revealed that the dormancy release of Chinese fir was at early April and the formation period of phloem tissue is earlier than xylem tissue.

Conductivity of the phloem in mango (Mangifera indica L.)

Mango (Mangifera indica L., Anacardiaceae), the fifth most consumed fruit worldwide, is one of the most important fruit crops in tropical regions, but its vascular anatomy is quite unexplored. Previous studies examined the xylem structure in the stems of mango, but the anatomy of the phloem has remained elusive, leaving the long-distance transport of photoassimilates understudied. We combined fluorescence and electron microscopy to evaluate the structure of the phloem tissue in the tapering branches of mango trees, and used this information to describe the hydraulic conductivity of its sieve tube elements following current models of fluid transport in trees. We revealed that the anatomy of the phloem changes from current year branches, where it was protected by pericyclic fibres, to older ones, where the lack of fibres was concomitant with laticiferous canals embedded in the phloem tissue. Callose was present in the sieve plates, but also in the walls of the phloem sieve cells, making them discernible from other phloem cells. A scaling geometry of the sieve tube elements—including the number of sieve areas and the pore size across tapering branches—resulted in an exponential conductivity towards the base of the tree. These evaluations in mango fit with previous measurements of the phloem architecture in the stems of forest trees, suggesting that, despite agronomic management, the phloem sieve cells scale with the tapering branches. The pipe model theory applied to the continuous tubing system of the phloem appears as a good approach to understand the hydraulic transport of photoassimilates in fruit trees.

Conductivity of the phloem in Mangifera indica L.

ABSTRACTMangifera indica is the fifth most consumed fruit worldwide, and the most important in tropical regions, but its anatomy is quite unexplored. Previous studies examined the effect of chemicals on the xylem structure in the stems of mango, but the anatomy of the phloem has remained elusive, leaving the long distance transport of photo assimilates understudied.In this work, we used a combination of fluorescence and electron microscopy to evaluate in detail the structure of the sieve tube elements composing the phloem tissue in the tapering branches of mango trees. We then used this information to better understand the hydraulic conductivity of the sieve tubes following current models of fluid transport in trees.Our results revealed that the anatomy of the phloem in the stems changes from current year branches, where it was protected by pericyclic fibers, to older ones, where the lack of fibers was concomitant with laticiferous canals embedded in the phloem tissue. Callose was present in the sieve plates, but also in the walls of the phloem conduits, making them discernible from other phloem cells in fresh sections. A scaling geometry of the sieve tube elements, including the number of sieve areas and the pore size across tapering branches resulted in an exponential conductivity from current year branches to the base of the tree.Our measurements of the phloem in mango fit with measurements of the phloem architecture in the stems of forest woody species, and imply that, despite agronomic pruning practices, the sieve conduits of the phloem scale with the tapering branches. As a result, the pipe model theory applied to the continuous tubing system of the phloem appears as a good approach to understand the “long distance” hydraulic transport of photoassimilates in fruit trees.

Macroscopic-microscopic characteristics and AFLP fingerprint for identification of Erythroxylum novogranatense, E. cambodianum and E. cuneatum endemic to Thailand

Erythroxylum novogranatense (Morris) Hieron, E. cambodianum Pierre and E. cuneatum (Miq.) Kurz in family Erythroxylaceae was traditionally used as an antipyretic, general stimulant and gastrointestinal diseases. Due to their morphological similarity, the correct identification was necessary for the quality control in herbal medicine. E. novogranatense (Morris) Hieron, E. cambodianum Pierre and E. cuneatum (Miq.) Macroscopic and microscopic characteristics evaluated Kurz endemic to Thailand according to WHO standard guideline and amplified fragment length polymorphism (AFLP) fingerprint. Morphological characters of E. novogranatense, E. cambodianum and E. cuneatum were similar in their flower, fruit and seed but different in stem and leaf. Microscopic characteristics from these three species, including constant leaf numbers, showed individual values. The stomata were classified as paracytic type. The midrib transverse section showed distinct characters of the epidermis, palisade cell, stomata, spongy cell, parenchyma, xylem vessel, phloem tissue and collenchyma. AFLP fingerprint showed highly polymorphisms 97.42% with the number of bands (349 bands) ranging between 50-750 bands. Primer E+ACG/M+CTT had the highest number of AFLP band (91 bands). The dendrogram generated from UPGMA could separate these three species. In summary, the combination of morphological characteristics, microscopic investigation and AFLP fingerprinting can be used to identify plant species and determine the genetic relationship among three Erythroxylum species.

Doğu Akdeniz Bölgesi Kiraz Üretim Alanlarında Cicadellidae (Hemiptera) Familyasına Ait Türlerin Belirlenmesi

Sweet cherry (Prunus avium L.) is highly valued fruit in the world and has wide production area in Turkey. Some of the species from the family Cicadellidae can cause direct damage by sucking the sap, and indirect damage by transmitting the phytoplasmas during their feeding process on the sweet cherry trees. This study was conducted to investigate the presence of the species of Cicadellidae family in Adana (Pozantı), Niğde (Darboğaz) and Kahramanmaraş (Andırın and Central Town), where sweet cherry cultivation is carried out, through 2014-2016. Surveying was done in two period a year, in spring (May-June) and fall (October-November) on the trees and weeds. As a result of sampling, 55 species from 35 genus in Cicadellidae were found. They are 32 species from Deltocephalinae subfamily, 18 species from Typhlocybinae, 4 species from Agallinae and 1 species from Megophthalminae subfamily were identified. Among them, Psammotettix striatus (Linnaeus) was the most common species with the 45.79% in total, followed by P. provincialis (Ribaut) with 15.26%. The other species were Empoasca sp. and Asymmetrasca decedens (Paoli) with 7.15% and 6.63%, respectively. It is known that the Phytoplasmas are phloem-limited agents, so, the cicadellid species that are feeding phloem tissue of the plant can acquire the pathogen and be able to transmit the phytoplasma potentially. As a result, it could be concluded that studies are needed to determine the potential to be vector of species of Deltocephalinae determined in sweet cherry orchards.

Identification and Functional Characterization of PtoMYB055 Involved in the Regulation of the Lignin Biosynthesis Pathway in Populus tomentosa

Wood, which is mainly composed of lignified secondary cell wall, is the most abundant biomass in woody plants. Previous studies have revealed that R2R3-type MYB transcription factors are important regulators of the formation of the secondary cell wall in vascular plants. In this study, we isolated the R2R3-type MYB transcription factor gene PtoMYB055, which is mainly expressed in xylem and phloem tissue, from Populus tomentosa and demonstrate that PtoMYB055 is a key regulator of lignin biosynthesis. PtoMYB055 as a transcriptional activator is localized to the nucleus. Overexpression of PtoMYB055 upregulates expression of lignin biosynthetic genes in transgenic poplar plants, resulting in ectopic deposition of lignin in phloem tissue and an increase in thickness of the secondary cell wall. In sum, PtoMYB055 is a transcriptional activator that is involved in regulating lignin biosynthesis during the formation of the secondary cell wall in poplar.

Nickel hyperaccumulation in New Caledonian Hybanthus (Violaceae) and occurrence of nickel-rich phloem in Hybanthus austrocaledonicus

Background and Aims Hybanthus austrocaledonicus (Violaceae) is a nickel (Ni) hyperaccumulator endemic to New Caledonia. One of the specimens stored at the local herbarium had a strip of bark with a remarkably green phloem tissue attached to the sheet containing over 4 wt% Ni. This study aimed to collect field samples from the original H. austrocaledonicus locality to confirm the nature of the green ‘nickel-rich phloem’ in this taxon and to systematically assess the occurrence of Ni hyperaccumulation in H. austrocaledonicus and Hybanthus caledonicus populations. Methods X-ray fluorescence spectroscopy scanning of all collections of the genus Hybanthus (236 specimens) was undertaken at the Herbarium of New Caledonia to reveal incidences of Ni accumulation in populations of H. austrocaledonicus and H. caledonicus. In parallel, micro-analytical investigations were performed via synchrotron X-ray fluorescence microscopy (XFM) and scanning electron microscopy with X-ray microanalysis (SEM-EDS). Key Results The extensive scanning demonstrated that Ni hyperaccumulation is not a characteristic common to all populations in the endemic Hybanthus species. Synchrotron XFM revealed that Ni was exclusively concentrated in the epidermal cells of the leaf blade and petiole, conforming with the majority of (tropical) Ni hyperaccumulator plants studied to date. SEM-EDS of freeze-dried and frozen-hydrated samples revealed the presence of dense solid deposits in the phloem bundles that contained &gt;8 wt% nickel. Conclusions The occurrence of extremely Ni-rich green phloem tissues appears to be a characteristic feature of tropical Ni hyperaccumulator plants.

Testing different methods for the extraction and purification of leaf and phloem sugars for oxygen isotope analysis

&lt;p&gt;Oxygen isotope analysis of plant material, such as sugars in different tissues, provides an important tool to understand how plants function, interact with their environment and also cope with climate change. Knowing how to extract and purify carbohydrates without artificially altering their oxygen isotope ratio (&lt;em&gt;&amp;#948;&lt;/em&gt;&lt;sup&gt;18&lt;/sup&gt;O) is therefore essential.&lt;/p&gt;&lt;p&gt;We aimed to resolve the impact of different steps on sugars' &lt;em&gt;&amp;#948;&lt;/em&gt;&lt;sup&gt;18&lt;/sup&gt;O values during their extraction and purification from leaf and phloem tissue. More precisely, we investigated (1) different drying processes (oven- vs freeze-drying), and (2) how extraction and purification affect leaf sugars. To clearly see fractionation and exchange processes, these experiments were performed using &lt;sup&gt;18&lt;/sup&gt;O-labelled water. We further examined (3) the influence of different EDTA media and immersion times to facilitate sugar exudation and subsequent yield from twig phloem tissue. Finally, we analysed (4) the sugar phloem composition, as well as the individual compounds&amp;#8217; carbon isotopic signatures (&lt;em&gt;&amp;#948;&lt;/em&gt;&lt;sup&gt;13&lt;/sup&gt;C).&lt;/p&gt;&lt;p&gt;Comparison of freeze- and oven-dried sugars showed lower &lt;em&gt;&amp;#948;&lt;/em&gt;&lt;sup&gt;18&lt;/sup&gt;O memory effects and more consistent oxygen isotopic signatures across different sugars, indicating lyophilisation as the more reliable method. The extraction and purification can be conducted without significant oxygen isotope fractionation. However, &lt;sup&gt;18&lt;/sup&gt;O-depletion was observed when sugars were dissolved and dried multiple times. This suggests that additional dissolution and drying steps should best be avoided whenever possible. Different immersion times and exudation media during twig phloem extraction revealed to have a substantial influence on the phloem sugars' overall oxygen isotopic signature, their composition, and the individual compounds' &lt;em&gt;&amp;#948;&lt;/em&gt;&lt;sup&gt;13&lt;/sup&gt;C values.&lt;/p&gt;&lt;p&gt;Our research illustrates which precautions during sample preparation &amp;#8211; from drying to extracting and purifying &amp;#8211; need to be taken when plant sugars and their oxygen isotopic signature are of interest. Regarding the preservation of the phloem sugars' original &lt;em&gt;&amp;#948;&lt;/em&gt;&lt;sup&gt;18&lt;/sup&gt;O values and stabilising their composition (prevention of sucrose degradation) as much as possible, we recommend a short immersion time of approx. 1 hour. After a thorough initial rinse of the tissue, the sap should be eluted in pure water without any additives (no EDTA). This further reduces the possibility of hexoses to exchange oxygen with that of the surrounding water.&lt;/p&gt;