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

Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1552
Author(s):  
Jiangtao Shi ◽  
Chongyang Xia ◽  
Junyi Peng ◽  
Xing Liu ◽  
Biao Pan

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.

IAWA Journal ◽  
2013 ◽  
Vol 34 (2) ◽  
pp. 183-196 ◽  
Author(s):  
Anne-Laure Decombeix

Our knowledge of the evolution of secondary phloem and periderm anatomy in early lignophytes (progymnosperms and seed plants) is limited by the scarcity of well-preserved fossil bark. Here, I describe the bark of a Mississippian (Early Carboniferous) tree from Australia based on macro- and microscopic observation of two permineralized specimens. The bark tissues are up to 1.5 cm in thickness. The secondary phloem is organized in repeated, multicellular tangential layers of fibers and of thin-walled cells that correspond to axial parenchyma and sieve cells. Fibers are abundant even in the youngest, presumably functional, secondary phloem. Older phloem shows a proliferation of axial parenchyma that further separates the fiber layers. Successive periderm layers originate deep within the phloem and lead to the formation of a rhytidome-type bark, one of the oldest documented in the fossil record. These fossils add to our knowledge of the bark anatomy of Early Carboniferous trees, previously based on a few specimens from slightly younger strata of Western Europe. The complexity of the secondary phloem tissue in Devonian-Carboniferous lignophytes and possible anatomical differences related to growth habit are discussed.


1968 ◽  
Vol 16 (3) ◽  
pp. 419 ◽  
Author(s):  
S Zee

The pattern of distribution and differentiation of the primary phloem, the cambium, and the secondary phloem, and the exact pattern of division of the initial cell and its derivatives have been studied in the epicotyl of pea plants by using electron microscopy. Three divisional patterns of the initial cell, in giving rise to the phloem cells, are recognized. The initial cell first divides periclinally to give rise to a transitional cell. This transitional cell then divides further (periclinally and/or anticlinally) to give rise to three sequences of phloem derivatives: (1) phloem parenchyma cells, (2) a companion cell and a sieve cell, and (3) a companion cell, a sieve cell, and a phloem parenchyma cell. The derived cells can all easily be distinguished from each other either by their position in the vascular bundle at low magnification or by the different types of plastids present in them. The general pattern of differentiation of the cytoplasm and the formation of the sieve plate and the sieve pores of the sieve element are essentially similar in the primary and the secondary phloem. However, the sieve element of the secondary phloem, unlike that of the primary phloem, possesses in its cytoplasm three kinds of inclusion bodies - an amorphous form, a "crystalline" form, and a tubular form; these are described and their nature discussed.


Author(s):  
Patrick Echlin ◽  
Thomas Hayes ◽  
Clifford Lai ◽  
Greg Hook

Studies (1—4) have shown that it is possible to distinguish different stages of phloem tissue differentiation in the developing roots of Lemna minor by examination in the transmission, scanning, and optical microscopes. A disorganized meristem, immediately behind the root-cap, gives rise to the vascular tissue, which consists of single central xylem element surrounded by a ring of phloem parenchyma cells. This ring of cells is first seen at the 4-5 cell stage, but increases to as many as 11 cells by repeated radial anticlinal divisions. At some point, usually at or shortly after the 8 cell stage, two phloem parenchyma cells located opposite each other on the ring of cells, undergo an unsynchronized, periclinal division to give rise to the sieve element and companion cell. Because of the limited number of cells involved, this developmental sequence offers a relatively simple system in which some of the factors underlying cell division and differentiation may be investigated, including the distribution of diffusible low atomic weight elements within individual cells of the phloem tissue.


IAWA Journal ◽  
1996 ◽  
Vol 17 (2) ◽  
pp. 141-150 ◽  
Author(s):  
Elsa Nunes ◽  
Teresa Quilhó ◽  
Helena Pereira

The secondary phloem of Pinus pinaster Aiton bark has sieve cells and axial and radial parenchyma, but no fibres. Resin ducts are present in fusiform rays . Stiloid crystals, starch granules and tannins occur inside sieve and parenchyma cells. The rhytidome of P. pinaster bark has a variable number of periderms forming scale-type discontinuous layers over expanded parenchyma cells. Phellem comprises 4-6 layers of thickwaIled and little suberized cells and phelloderm a layer of 2 or 3 thickened lignified ceIls and a layer of expanded cells.


1970 ◽  
Vol 48 (2) ◽  
pp. 341-359 ◽  
Author(s):  
Lalit M. Srivastava

The origin of sieve elements and parenchyma cells in the secondary phloem of Austrobaileya was studied by use of serial cross sections stained with tannic acid – ferric chloride and lacmoid. In three important respects, Austrobaileya phloem recalls gymnospermous features: it has sieve cells rather than sieve-tube members; a significant proportion of sieve elements and companion cells arise independently of each other; and sieve areas occur between sieve elements and companion cells ontogenetically unrelated to each other. The angiospermous feature includes origin of most sieve elements and parenchyma, including companion cells, after divisions in phloic initials. In these instances companion cells show a closer ontogenetic relationship to sieve elements than do other parenchyma cells. The combination of gymnospermous and angiospermous features makes phloem of Austrobaileya unique when compared to that of all those species that have been investigated in detail. It is further suggested that the term albuminous cells is inappropriate and should be replaced by companion cells but that the ontogenetic relationship implicit in the definition of companion cells is too restrictive and should be abandoned.


1999 ◽  
Vol 47 (4) ◽  
pp. 245-250 ◽  
Author(s):  
Ishwar D. Garg ◽  
S.M. Paul Khurana

The tospovirus isolate on tomato was found to be systemic while the one on potato was non-systemic. The virus was present in all the tissues except xylem vessels in tomato, while it was often found only in the cortical cells of potato stems. Virions were detected in all cells of phloem tissue in tomato, while none were present in the case of potato. Plasmodesmata were present between phloem parenchyma and the phloem sieve tubes in infected tomato but none were present in infected potato. There were pronounced plasmodesmal changes in response to infection in tomato. These included dissolution of the desmotubule (central rod-like structure), making the plasmodesmata pore-like structures with a diameter of ca. 45 nm, which contained electron-dense material, presumably ribonucleoprotein of the virus. No such changes were found in infected potato. These results of comparative studies suggested that the virus was non-systemic in potato due to its non-loading into the phloem and consequently lacked long distance transport.


IAWA Journal ◽  
1987 ◽  
Vol 8 (3) ◽  
pp. 191-201 ◽  
Author(s):  
Michael A. Millay ◽  
Thomas N. Taylor ◽  
Edith L. Taylor

Primary anatomy and secondary development is described for two root types from the Fremouw Peak locality (Transantarctic Mts, Antarctica) of early to middle Triassic age. Roots of Antarcticycas have a bilayered cortex with thick surface cuticle, diarch xylem, and a clearIy defined endodermis surrounded by a single cell layer possessing phi thickenings. Secondary development begins with phellern and phelloderm production from the out er primary phloem position, and is followed bya bifacial vascular cambium next to the primary xylem that pro duces sieve cells and ray parenchyma to the outside. Young roots of Antarcticoxylon are similar to those of Antarcticycas, but may possess 2-3 cell layers with phi thickenings. Secondary development from a bifacial vascular cambium produces alternating bands of sieve cells and phloem parenchyma cells in the secondary phloem and wood with uniseriate rays and scattered axial parenchyma. The presence of phi thickenings and an epidermal cutieie in both roots suggests environmental stress related to water regulation. The occurrence of phi thickenings in the roots of some conifers, angiosperms, a fossil cycad and a probable seed fern suggests this character is of ecological rather than phylogenetic significance.


1979 ◽  
Vol 57 (12) ◽  
pp. 1340-1344 ◽  
Author(s):  
Thompson Demetrio Pizzolato ◽  
David L. Regehr

An aqueous spray of 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB) induces anatomical changes in young Glycine internodes. Four days after spraying, the first symptoms appear outside the cambium when the interfascicular parenchyma cells and the adjacent cortical parenchyma cells enlarge and divide in several planes. Four days later, the metaphloem parenchyma cells in many of the leaf traces undergo considerable periclinal cell division and extensive radial cell enlargement. The phloem parenchyma cells of the late metaphloem and first secondary phloem enlarge and divide in a less orderly fashion. Fifteen days after treatment, the cortical parenchyma is modified into a band of radially seriate cells above the protophloem fibers. Products of this cambium-like region convert the cortex into a callus-like tissue. The size of starch grains is reduced initially in the phloem and xylem and later in the cortex. It appears that the stimuli produced by 2,4-DB move into the internode via the metaphloem of leaf traces. Despite the rapid obliteration of conducting phloem by the 2,4-DB induced stimulation of phloem parenchyma, an accelerated differentiation of secondary phloem compensates for this loss.


Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1326
Author(s):  
Xinjie Cui ◽  
Junji Matsumura

Information on the weathering behaviour of Cunninghamia lanceolata (Lamb.) Hook. is needed to provide references for wood weatherproof pre-treatment and to improve wood utilization. Therefore, this study was conducted to understand the variation in the intrinsic weathering behaviour of Cunninghamia lanceolata (Chinese fir) under natural conditions. Wood samples from 15 Cunninghamia lanceolata trees aged 26–30 years old were used. The structural degradation and discoloration of wood surfaces before and after exposure were compared. The results show that the weathering behaviour of wood was weakened from heartwood to sapwood and enhanced from the bottom to the top. This study provided information for weatherability research and improved wood utilization of Cunninghamia lanceolata.


IAWA Journal ◽  
2003 ◽  
Vol 24 (4) ◽  
pp. 421-428
Author(s):  
Wei-Min Tian ◽  
Zheng-Hai Hu

The distribution pattern of vegetative storage proteins is reported for the first time for 18 species and 2 varieties of twelve genera of Rosaceae. Vegetative storage proteins were present in all the species studied of Prunoideae and absent in Maloideae. Their occurrence in a genus seemed to be either universal or entirely absent. Rosaceae trees were poor in vegetative storage proteins and the form of vegetative storage proteins was not protein body-like. Granular and floccular forms of vegetative storage proteins could be distinguished exclusively in the secondary phloem parenchyma cells and their distribution was cell-specific. Our results suggest that the distribution of vegetative storage proteins in Rosaceae can be considered as a taxonomically diagnostic feature. The nature of the bark proteins with seasonal changes in apple trees is discussed.


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