DNA synthesis and cell divisions in the quiescent center as well as initiation of lateral root primordia were investigated in the course of incubation of the roots of 3-day-old wheat (Triticum aestivum L.) seedlings on the medium with 0.1 mM NiSO4 for 72 h. It was found that the earliest effect of nickel on proliferation of the quiescent center cells was associated with an increase in the mitotic index 6 h after the beginning of its action. This effect was assumed to depend on an increase in mitosis time. Twelve hours after the beginning of the effect of nickel, mitotic index became somewhat lower, and in 18 h it sharply decreased. Some dividing cells were observed among the initial cells of certain tissues and near the quiescent center even in 72 h. The portion of DNA synthesizing cell sharply decreased in 12 h, and in 48 h such cells were lacking. The main mechanism governing the termination of cell proliferation in the quiescent center as well as in the meristem and calyptrogen of the cap is the inhibition of cell transition to DNA synthesis. The cells that had time to start DNA synthesis or already finished it and were in other phases of the cycle continued a slow progression through the cycle and completed it. Sister cells, produced as a result of divisions, left the mitotic cycle in the phase G1 and transited to dormancy. Nickel did not inhibit initiation and development of lateral root primordia. Resumption of DNA synthesis and cell divisions occurred not only in the pericycle and endodermis participating in the initiation of lateral root primordia but also in the cortex cells in the vicinity of developing primordia. In 18 h after the beginning of the experiment when the rate of the root growth considerably decreased, the region, where primordia were initiated, was located closer to the root tip. Subsequently, when elongation of the cells was inhibited, this region moved closer to the tip until structural disturbances occurred in the nuclei of the endodermal cells located near the root tip and elongated under the effect of nickel. The results concerning the effect of nickel and other heavy metals on root cell proliferation obtained by other researchers and the role of pericycle organization in the translocation and accumulation of nickel in the tissues are discussed.
Russian Journal of Plant Physiology – Springer Journals
Published: May 9, 2010
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
Get unlimited, online access to over 18 million full-text articles from more than 15,000 scientific journals.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera