Thermostability of chlorophylls in some native species of xerophytes

Abstract

This study was carried out on eight wild species inhabited the tributaries of wadi Al Noman, at Holey Mecca in the western Kingdom of Saudi Arabia. The plant samples were collected at different locations, where laboratory analyses were included: the water content, chlorophyll content and its stability (CSI), , Mg ions, water soluble sugars and soluble proteins. The results showed that, the chlorophyll a content was higher than the chlorophyll b in the studied species. The maximum value of chlorophylls existed in C. colocyanthis and R. viscarius, whereas C. russeliana had low content of chlorophyll a and chlorophyll b. The chlorophyll a/b ratio was balanced by the chlorophyll stability to heat. The CSI of chlorophyll a was compensated by CSI of chlorophyll b and vice versa. The maximum values of total chlorophyll stability (a + b) was found in annuals C. colocynthis and D. innoxia, whereas C. russeliana had low CSI. The different chlorophyll parameters were mainly affected by the interaction between wadi and species, and the species factor played the subsidiary role on the chlorophyll content and chlorophyll a/b ratio in most floristic groups, except in case of chlorophyll a of dominant species the wadi factor was subsidiary. There was no significant effect of single factor on CSI of different groups. The correlation of Mg ions, soluble sugars and soluble proteins with total chlorophyll content and CSI were discussed.

Seasonal behavior of chlorophyll in some shrubs grown under mesic and xeric habitat conditions

“…In general, the total chlorophyll stability in studied shrubs was higher at xeric habitat compared to those at mesic habitat. Therefore, the increase in CSI and /or chlorophyll contents was referred to the high efficiency of photosynthetic apparatus in plants survives extreme conditions [5]. F values indicated that, the single factors and interactions (with some exceptions) had a significant effects on the CSI a, CSI b and total CSI of investigated species.…”

“…had a dominant role on the Mg +2 contents and the habitat factor role was subsidiary. Therefore, the interaction between the environmental factors played the major role on the Mg +2 contents in plants [3]; [5].…”

“…Consequently, the adaptation of plants in their natural habitats to enduring the drastic conditions contributed to decreased Chl. a/b ratio balanced by increased chlorophyll thermo-stability [5]. Hence, the strategies of plants against Chl.…”

Specific Activity of Streptomyces albus Preparations for Bioreguilation of Cucumber Plant

“…Ðå÷îâèíè, ÿê³ âèçíà÷àëè (õëîðîô³ëè, êàðî-òèíî¿äè, ïðîë³í), º ³íäèêàòîðàìè ñòàíó ðîñëèí, à ¿õ âì³ñò ñâ³ä÷èòü ïðî ïåðåá³ã ìåòàáîë³çìó â ðîñëèí³ òà õàðàêòåð âïëèâó çîâí³øí³õ ôàêòîð³â [15][16][17]. Âñòàíîâëåíî (ðèñ.…”

“…Çàãàëîì ï³äâèùåííÿ âì³ñòó õëîðîô³ë³â ñâ³ä-÷èòü ïðî ï³äâèùåííÿ ³íòåíñèâíîñò³ ìåòàáîë³çìó â ðîñëèí³, àëå äëÿ ïðîöåñó ôîòîñèíòåçó á³ëüø âàaeëèâèì º íå àáñîëþòíèé âì³ñò ï³ãìåíò³â, à ¿õ ñï³ââ³äíîøåííÿ. Âîíè ìîaeóòü ïîêàçóâàòè ïîðóøåííÿ ó ôóíêö³îíóâàíí³ ñâ³òîçáèðàëüíèõ êîìï- ëåêñ³â ³ ðåàêö³éíèõ öåíòð³â ôîòîñècòåì (ñï³â-â³äíîøåííÿ õëîðîô³ë³â à/b), à òàêîae ñò³éê³ñòü õëîðîô³ë³â äî ôîòîðóéíóâàííÿ, ÿêà âèçíà÷àºòüñÿ ê³ëüê³ñòþ êàðîòèíî¿ä³â, çäàòíèõ çàõèùàòè õëîðîô³ëè [16]. Òîìó ðîçðàõîâóâàëè é àíàë³çóâàëè ñï³ââ³äíîøåííÿ âì³ñòó õëîðîô³ë³â à/b ³ õëî-ðîô³ë³â äî êàðîòèíî¿ä³â.…”